This page has only limited features, please log in for full access.

Unclaimed
Yoonmook Kang
Graduate School of Energy and Environment (KU-KIST Green School), Korea University, Seoul 02841, Korea

Basic Info

Basic Info is private.

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 30 July 2021 in Energies
Reads 0
Downloads 0

The potential-induced degradation (PID) mechanism in Cu(In,Ga)(Se,S)2 (CIGS) thin-film solar cells, which are alternative energy sources with a high efficiency (>23%) and upscaling possibilities, remains unclear. Therefore, the cause of PID in CIGS solar cells was investigated in this study at the cell level. First, an appropriate PID experiment structure at the cell level was determined. Subsequently, PID and recovery tests were conducted to confirm the PID phenomenon. Light current–voltage (I–V), dark I–V, and external quantum efficiency (EQE) analyses were conducted to determine changes in the cell characteristics. In addition, capacitance–voltage (C–V) measurements were carried out to determine the doping concentration and width of the space charge region (SCR). Based on the results, the causes of PID and recovery of CIGS solar cells were explored, and it was found that PID occurs due to changes in the bulk doping concentration and built-in potential at the junction. Furthermore, by distinguishing the effects of temperature and voltage, it was found that PID phenomena occurred when potential difference was involved.

ACS Style

Solhee Lee; Soohyun Bae; Se Park; Jihye Gwak; Jaeho Yun; Yoonmook Kang; Donghwan Kim; Young-Joo Eo; Hae-Seok Lee. Characterization of Potential-Induced Degradation and Recovery in CIGS Solar Cells. Energies 2021, 14, 4628 .

AMA Style

Solhee Lee, Soohyun Bae, Se Park, Jihye Gwak, Jaeho Yun, Yoonmook Kang, Donghwan Kim, Young-Joo Eo, Hae-Seok Lee. Characterization of Potential-Induced Degradation and Recovery in CIGS Solar Cells. Energies. 2021; 14 (15):4628.

Chicago/Turabian Style

Solhee Lee; Soohyun Bae; Se Park; Jihye Gwak; Jaeho Yun; Yoonmook Kang; Donghwan Kim; Young-Joo Eo; Hae-Seok Lee. 2021. "Characterization of Potential-Induced Degradation and Recovery in CIGS Solar Cells." Energies 14, no. 15: 4628.

Journal article
Published: 26 May 2021 in Energies
Reads 0
Downloads 0

Monolithic perovskite–silicon tandem solar cells with MoOx hole selective contact silicon bottom solar cells show a power conversion efficiency of 8%. A thin 15 nm-thick MoOx contact to n-type Si was used instead of a standard p+ emitter to collect holes and the SiOx/n+ poly-Si structure was deposited on the other side of the device for direct tunneling of electrons and this silicon bottom cell structure shows ~15% of power conversion efficiency. With this bottom carrier selective silicon cell, tin oxide, and subsequent perovskite structure were deposited to fabricate monolithic tandem solar cells. Monolithic tandem structure without ITO interlayer was also compared to confirm the role of MoOx in tandem cells and this tandem structure shows the power conversion efficiency of 3.3%. This research has confirmed that the MoOx layer simultaneously acts as a passivation layer and a hole collecting layer in this tandem structure.

ACS Style

Hoyoung Song; Changhyun Lee; Jiyeon Hyun; Sang-Won Lee; Dongjin Choi; DoWon Pyun; Jiyeon Nam; Seok-Hyun Jeong; Jiryang Kim; Soohyun Bae; Hyunju Lee; Yoonmook Kang; Donghwan Kim; Hae-Seok Lee. Monolithic Perovskite-Carrier Selective Contact Silicon Tandem Solar Cells Using Molybdenum Oxide as a Hole Selective Layer. Energies 2021, 14, 3108 .

AMA Style

Hoyoung Song, Changhyun Lee, Jiyeon Hyun, Sang-Won Lee, Dongjin Choi, DoWon Pyun, Jiyeon Nam, Seok-Hyun Jeong, Jiryang Kim, Soohyun Bae, Hyunju Lee, Yoonmook Kang, Donghwan Kim, Hae-Seok Lee. Monolithic Perovskite-Carrier Selective Contact Silicon Tandem Solar Cells Using Molybdenum Oxide as a Hole Selective Layer. Energies. 2021; 14 (11):3108.

Chicago/Turabian Style

Hoyoung Song; Changhyun Lee; Jiyeon Hyun; Sang-Won Lee; Dongjin Choi; DoWon Pyun; Jiyeon Nam; Seok-Hyun Jeong; Jiryang Kim; Soohyun Bae; Hyunju Lee; Yoonmook Kang; Donghwan Kim; Hae-Seok Lee. 2021. "Monolithic Perovskite-Carrier Selective Contact Silicon Tandem Solar Cells Using Molybdenum Oxide as a Hole Selective Layer." Energies 14, no. 11: 3108.

Journal article
Published: 15 December 2020 in Energies
Reads 0
Downloads 0

The etching of Si wafers significantly influences the efficiency of photovoltaic devices. Texturing can effectively decrease front surface reflection and improve device performance. Saw damage removal (SDR) is necessary to yields uniform random pyramidal surfaces without the appearance of saw marks, it entails significant consumption of chemical solutions and complicated cleaning steps. Herein, an alternative process of pre-texturing thermal treatment was carried out at 800 °C for 10 min, followed by anisotropic texturing, and a uniform pyramidal surface over a large area of the textured surface was obtained without saw marks. Compared with that of as-cut mono-Si wafers (30.7%), the weighted average reflectance of the samples textured with or without thermal treatment decreased to 11.2% and 11.9%, respectively, and further to 3% and 3.4%, respectively, when anti-reflection coatings were applied. In addition, saw marks on the wafer surface were used as gettering sites during thermal treatment, and the bulk lifetime was more than doubled from 42.6 µs before the treatment to 93.8 µs after. The simple, SDR-free method presented herein for enhancing the textural uniformity of Si wafers and, hence, solar cell performance, can be employed on an industrial scale without necessitating additional investment in equipment.

ACS Style

Yujin Jung; Kwanhong Min; Soohyun Bae; Myeongseob Sim; Yoonmook Kang; Haeseok Lee; Donghwan Kim. Pre-Texturing Thermal Treatment for Saw-Damage-Removal-Free Wet Texturing of Monocrystalline Silicon Wafers. Energies 2020, 13, 6610 .

AMA Style

Yujin Jung, Kwanhong Min, Soohyun Bae, Myeongseob Sim, Yoonmook Kang, Haeseok Lee, Donghwan Kim. Pre-Texturing Thermal Treatment for Saw-Damage-Removal-Free Wet Texturing of Monocrystalline Silicon Wafers. Energies. 2020; 13 (24):6610.

Chicago/Turabian Style

Yujin Jung; Kwanhong Min; Soohyun Bae; Myeongseob Sim; Yoonmook Kang; Haeseok Lee; Donghwan Kim. 2020. "Pre-Texturing Thermal Treatment for Saw-Damage-Removal-Free Wet Texturing of Monocrystalline Silicon Wafers." Energies 13, no. 24: 6610.

Journal article
Published: 16 November 2020 in IEEE Journal of Photovoltaics
Reads 0
Downloads 0
ACS Style

Yujin Jung; Jongwon Ko; Soohyun Bae; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. Effective Surface Texturing of Diamond-Wire-Sawn Multicrystalline Silicon Wafers Via Crystallization of the Native Surface Amorphous Layer. IEEE Journal of Photovoltaics 2020, 11, 43 -49.

AMA Style

Yujin Jung, Jongwon Ko, Soohyun Bae, Yoonmook Kang, Hae-Seok Lee, Donghwan Kim. Effective Surface Texturing of Diamond-Wire-Sawn Multicrystalline Silicon Wafers Via Crystallization of the Native Surface Amorphous Layer. IEEE Journal of Photovoltaics. 2020; 11 (1):43-49.

Chicago/Turabian Style

Yujin Jung; Jongwon Ko; Soohyun Bae; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. 2020. "Effective Surface Texturing of Diamond-Wire-Sawn Multicrystalline Silicon Wafers Via Crystallization of the Native Surface Amorphous Layer." IEEE Journal of Photovoltaics 11, no. 1: 43-49.

Journal article
Published: 09 November 2020 in IEEE Journal of Photovoltaics
Reads 0
Downloads 0

The introduction of diamond wire sawing (DWS) technology has resulted in significant cost reduction in the fabrication of crystalline silicon wafers. However, the DWS process results in parallel wheel marks, saw damage, and formation of an amorphous silicon layer on the surface, which causes difficultly in effectively forming the desired surface texture using conventional acidic etching (also known isotropic etching) techniques for multicrystalline silicon (mc-Si) wafers. In this study, we propose a novel pretreatment grinding (NPTG) technique as a method to address such issues. This is a relatively simple and inexpensive method that does not utilize processes that require the use of expensive equipment, such as vacuum equipment. Additionally, it makes use of environment-friendly procedures that do not require materials such as metal catalysts and additives that cause environmental pollution. The proposed NPTG method provides a good surface topology for effective texturing using a conventional acidic etching solution, and as a result, a uniform texture can be applied to DWS mc-Si wafers. Under the optimized experimental conditions in this study, a weighted average reflectance of 22.63% was achieved after the NPTG was applied. This reflected 6.67% less light than the 29.3% after conventional acidic texturing without the NPTG using DWS mc-Si wafers. Further, a solar cell fabricated using the DWS mc-Si wafers treated with the NPTG method achieved a cell efficiency of approximately 19.2%.

ACS Style

Yujin Jung; Kwan Hong Min; Soohyun Bae; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. 19.2%-Efficient Multicrystalline Silicon Solar Cells via Additive-Free Mechanical Grinding Surface Pretreatment for Diamond-Wire-Sawn Wafers. IEEE Journal of Photovoltaics 2020, 11, 36 -42.

AMA Style

Yujin Jung, Kwan Hong Min, Soohyun Bae, Yoonmook Kang, Hae-Seok Lee, Donghwan Kim. 19.2%-Efficient Multicrystalline Silicon Solar Cells via Additive-Free Mechanical Grinding Surface Pretreatment for Diamond-Wire-Sawn Wafers. IEEE Journal of Photovoltaics. 2020; 11 (1):36-42.

Chicago/Turabian Style

Yujin Jung; Kwan Hong Min; Soohyun Bae; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. 2020. "19.2%-Efficient Multicrystalline Silicon Solar Cells via Additive-Free Mechanical Grinding Surface Pretreatment for Diamond-Wire-Sawn Wafers." IEEE Journal of Photovoltaics 11, no. 1: 36-42.

Journal article
Published: 05 November 2020 in Energies
Reads 0
Downloads 0

In a multicrystalline silicon (mc-Si) wafer, trapping effects frequently occur in the carrier lifetime measurement based on the quasi-steady-state photoconductance (QSSPC) technique. This affects the accurate measurement of the carrier lifetime of an mc-Si solar cell by causing distortions at a low injection level close to the Pmax point. Therefore, it is necessary to understand this effect and effectively minimize the trapping-center density. In this study, the variations in the minority carrier-trapping effect of hydrogen at different annealing temperatures in an mc-Si were observed using QSSPC, time-of-flight secondary ion mass spectroscopy, and atom probe tomography. A trapping effect was confirmed and occurred in the grain boundary area, and the effect was reduced by hydrogen. Thus, in an mc-Si wafer, effective hydrogen passivation on the grain area and grain boundary is crucial and was experimentally proven to minimize the distortion of the carrier lifetime.

ACS Style

Yujin Jung; Kwan Hong Min; Soohyun Bae; Yoonmook Kang; Donghwan Kim; Hae-Seok Lee. Variations in Minority Carrier-Trapping Effects Caused by Hydrogen Passivation in Multicrystalline Silicon Wafer. Energies 2020, 13, 5783 .

AMA Style

Yujin Jung, Kwan Hong Min, Soohyun Bae, Yoonmook Kang, Donghwan Kim, Hae-Seok Lee. Variations in Minority Carrier-Trapping Effects Caused by Hydrogen Passivation in Multicrystalline Silicon Wafer. Energies. 2020; 13 (21):5783.

Chicago/Turabian Style

Yujin Jung; Kwan Hong Min; Soohyun Bae; Yoonmook Kang; Donghwan Kim; Hae-Seok Lee. 2020. "Variations in Minority Carrier-Trapping Effects Caused by Hydrogen Passivation in Multicrystalline Silicon Wafer." Energies 13, no. 21: 5783.

Journal article
Published: 05 November 2020 in ACS Applied Energy Materials
Reads 0
Downloads 0
ACS Style

Seung Hoon Lee; Min Kyu Kim; Soohyun Bae; Jiyeon Nam; Hyunjung Park; Sang-Won Lee; Yun Jung Jang; Byoung Koun Min; JungYup Yang; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. Absorber Delamination-Induced Shunt Defects in Alcohol-Based Solution-Processed Cu(In,Ga)(S,Se)2 Solar Modules. ACS Applied Energy Materials 2020, 3, 10384 -10392.

AMA Style

Seung Hoon Lee, Min Kyu Kim, Soohyun Bae, Jiyeon Nam, Hyunjung Park, Sang-Won Lee, Yun Jung Jang, Byoung Koun Min, JungYup Yang, Yoonmook Kang, Hae-Seok Lee, Donghwan Kim. Absorber Delamination-Induced Shunt Defects in Alcohol-Based Solution-Processed Cu(In,Ga)(S,Se)2 Solar Modules. ACS Applied Energy Materials. 2020; 3 (11):10384-10392.

Chicago/Turabian Style

Seung Hoon Lee; Min Kyu Kim; Soohyun Bae; Jiyeon Nam; Hyunjung Park; Sang-Won Lee; Yun Jung Jang; Byoung Koun Min; JungYup Yang; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. 2020. "Absorber Delamination-Induced Shunt Defects in Alcohol-Based Solution-Processed Cu(In,Ga)(S,Se)2 Solar Modules." ACS Applied Energy Materials 3, no. 11: 10384-10392.

Journal article
Published: 17 August 2020 in IEEE Journal of Photovoltaics
Reads 0
Downloads 0

Since the kerfless wafer method for manufacturing multicrystalline silicon (mc-Si) wafers does not involve a sawing process, there occurs no saw damage on the surface, and the product is characterized by a flat surface morphology. These wafers cannot be effectively textured under the conditions of a conventional acidic etching solution with stability or efficiency because the surfaces are free of the surface damage caused by sawing. The texturing process developed in this article uses a conventional acidic etching solution without additives and a metal catalyst; the resulting process is a novel double acidic texturing (DAT) process capable of texturing using hydrofluoric acid (HF), HNO $_{3}$ , CH $_{3}$ COOH, and deionized water. The kerfless wafers treated with this novel texturing treatment had a weighted average reflectance (R $_{w}$ ) of 25.40%, which is ∼5.76% less than that of kerfless wafers textured under conventional acidic texturing conditions (R $_{w}$ = ∼31.16%). A solar cell manufactured with the new DAT process showed an enhanced short-circuit current density (+2.65 mA·cm−2), fill factor (+3.87%), and efficiency (+2.18%) than those of a cell fabricated without using this novel double treatment.

ACS Style

Yujin Jung; Soohyun Bae; Hae-Seok Lee; Donghwan Kim; Yoonmook Kang. Novel Double Acidic Texturing Process for Saw-Damage-Free Kerfless Multicrystalline Silicon Wafers. IEEE Journal of Photovoltaics 2020, 10, 1545 -1551.

AMA Style

Yujin Jung, Soohyun Bae, Hae-Seok Lee, Donghwan Kim, Yoonmook Kang. Novel Double Acidic Texturing Process for Saw-Damage-Free Kerfless Multicrystalline Silicon Wafers. IEEE Journal of Photovoltaics. 2020; 10 (6):1545-1551.

Chicago/Turabian Style

Yujin Jung; Soohyun Bae; Hae-Seok Lee; Donghwan Kim; Yoonmook Kang. 2020. "Novel Double Acidic Texturing Process for Saw-Damage-Free Kerfless Multicrystalline Silicon Wafers." IEEE Journal of Photovoltaics 10, no. 6: 1545-1551.

Journal article
Published: 07 June 2020 in Energies
Reads 0
Downloads 0

Since the temperature of a photovoltaic (PV) module is not consistent as it was estimated at a standard test condition, the thermal stability of the solar cell parameters determines the temperature dependence of the PV module. Fill factor loss analysis of crystalline silicon solar cell is one of the most efficient methods to diagnose the dominant problem, accurately. In this study, the fill factor analysis method and the double-diode model of a solar cell was applied to analyze the effect of J01, J02, Rs, and Rsh on the fill factor in details. The temperature dependence of the parameters was compared through the passivated emitter rear cell (PERC) of the industrial scale solar cells. As a result of analysis, PERC cells showed different temperature dependence for the fill factor loss of the J01 and J02 as temperatures rose. In addition, we confirmed that fill factor loss from the J01 and J02 at elevated temperature depends on the initial state of the solar cells. The verification of the fill factor loss analysis was conducted by comparing to the fitting results of the injection dependent-carrier lifetime.

ACS Style

Kwan Hong Min; Taejun Kim; Min Gu Kang; Hee-Eun Song; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim; Sungeun Park; Sang Hee Lee. An Analysis of Fill Factor Loss Depending on the Temperature for the Industrial Silicon Solar Cells. Energies 2020, 13, 1 .

AMA Style

Kwan Hong Min, Taejun Kim, Min Gu Kang, Hee-Eun Song, Yoonmook Kang, Hae-Seok Lee, Donghwan Kim, Sungeun Park, Sang Hee Lee. An Analysis of Fill Factor Loss Depending on the Temperature for the Industrial Silicon Solar Cells. Energies. 2020; 13 (11):1.

Chicago/Turabian Style

Kwan Hong Min; Taejun Kim; Min Gu Kang; Hee-Eun Song; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim; Sungeun Park; Sang Hee Lee. 2020. "An Analysis of Fill Factor Loss Depending on the Temperature for the Industrial Silicon Solar Cells." Energies 13, no. 11: 1.

Journal article
Published: 08 April 2020 in Energies
Reads 0
Downloads 0

A thin silicon oxide (SiOx) layer (thickness: 1.5–2.0 nm) formed at an Al2O3/Si interface can enhance the interface properties. However, it is challenging to control the characteristics of thin SiOx layers because SiOx forms naturally during Al2O3 deposition on Si substrates. In this study, a ~1.5 nm-thick SiOx layer was inserted between Al2O3 and Si substrates by wet chemical oxidation to improve the passivation properties. The acidic solutions used for wet chemical oxidation were HCl:H2O2:H2O, H2SO4:H2O2:H2O, and HNO3. The thicknesses of SiOx layers formed in the acidic solutions were ~1.48, ~1.32, and ~1.50 nm for SiOx-HCl, SiOx-H2SO4, and SiOx-HNO3, respectively. The leakage current characteristics of SiOx-HNO3 were better than those of the oxide layers formed in the other acidic solutions. After depositing a ~10 nm-thick Al2O3 on an SiOx-acidic/Si structure, we measured the effective carrier lifetime using quasi steady-state photoconductance and examined the interfacial properties of Al2O3/SiOx-acidic/Si using surface carrier lifetime simulation and capacitance–voltage measurement. The effective carrier lifetime of Al2O3/SiOx-HNO3/Si was relatively high (~400 μs), resulting from the low surface defect density (2.35–2.88 × 1010 cm−2eV−1). The oxide layer inserted between Al2O3 and Si substrates by wet chemical oxidation helped improve the Al2O3/Si interface properties.

ACS Style

Kwan Hong Min; Sungjin Choi; Myeong Sang Jeong; Sungeun Park; Min Gu Kang; Jeong In Lee; Yoonmook Kang; Donghwan Kim; Hae-Seok Lee; Hee-Eun Song. Wet Chemical Oxidation to Improve Interfacial Properties of Al2O3/Si and Interface Analysis of Al2O3/SiOx/Si Structure Using Surface Carrier Lifetime Simulation and Capacitance–Voltage Measurement. Energies 2020, 13, 1803 .

AMA Style

Kwan Hong Min, Sungjin Choi, Myeong Sang Jeong, Sungeun Park, Min Gu Kang, Jeong In Lee, Yoonmook Kang, Donghwan Kim, Hae-Seok Lee, Hee-Eun Song. Wet Chemical Oxidation to Improve Interfacial Properties of Al2O3/Si and Interface Analysis of Al2O3/SiOx/Si Structure Using Surface Carrier Lifetime Simulation and Capacitance–Voltage Measurement. Energies. 2020; 13 (7):1803.

Chicago/Turabian Style

Kwan Hong Min; Sungjin Choi; Myeong Sang Jeong; Sungeun Park; Min Gu Kang; Jeong In Lee; Yoonmook Kang; Donghwan Kim; Hae-Seok Lee; Hee-Eun Song. 2020. "Wet Chemical Oxidation to Improve Interfacial Properties of Al2O3/Si and Interface Analysis of Al2O3/SiOx/Si Structure Using Surface Carrier Lifetime Simulation and Capacitance–Voltage Measurement." Energies 13, no. 7: 1803.

Journal article
Published: 05 February 2020 in Energies
Reads 0
Downloads 0

Recently, titanium oxide has been widely investigated as a carrier-selective contact material for silicon solar cells. Herein, titanium oxide films were fabricated via simple deposition methods involving thermal evaporation and oxidation. This study focuses on characterizing an electron-selective passivated contact layer with this oxidized method. Subsequently, the SiO2/TiO2 stack was examined using high-resolution transmission electron microscopy. The phase and chemical composition of the titanium oxide films were analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The passivation quality of each layer was confirmed by measuring the carrier lifetime using quasi-steady-state photoconductance, providing an implied open circuit voltage of 644 mV. UV–vis spectroscopy and UV photoelectron spectroscopy analyses demonstrated the band alignment and carrier selectivity of the TiO2 layers. Band offsets of ~0.33 and ~2.6 eV relative to the conduction and valence bands, respectively, were confirmed for titanium oxide and the silicon interface.

ACS Style

Changhyun Lee; Soohyun Bae; Hyunjung Park; Dongjin Choi; Hoyoung Song; Hyunju Lee; Yoshio Ohshita; Donghwan Kim; Yoonmook Kang; Hae-Seok Lee. Properties of Thermally Evaporated Titanium Dioxide as an Electron-Selective Contact for Silicon Solar Cells. Energies 2020, 13, 678 .

AMA Style

Changhyun Lee, Soohyun Bae, Hyunjung Park, Dongjin Choi, Hoyoung Song, Hyunju Lee, Yoshio Ohshita, Donghwan Kim, Yoonmook Kang, Hae-Seok Lee. Properties of Thermally Evaporated Titanium Dioxide as an Electron-Selective Contact for Silicon Solar Cells. Energies. 2020; 13 (3):678.

Chicago/Turabian Style

Changhyun Lee; Soohyun Bae; Hyunjung Park; Dongjin Choi; Hoyoung Song; Hyunju Lee; Yoshio Ohshita; Donghwan Kim; Yoonmook Kang; Hae-Seok Lee. 2020. "Properties of Thermally Evaporated Titanium Dioxide as an Electron-Selective Contact for Silicon Solar Cells." Energies 13, no. 3: 678.

Journal article
Published: 27 December 2019 in Energies
Reads 0
Downloads 0

Modern energy needs and the pressing issue of environmental sustainability have driven many research groups to focus on energy-generation devices made from novel nanomaterials. We have prepared platinum nanoparticle-decorated silicon nanowire/carbon core–shell nanomaterials (SiNW/[email protected]). The processing steps are relatively simple, including wet chemical etching to form the silicon nanowires (SiNWs), chemical vapor deposition to form the carbon shell, and drop-casting and thermal treatment to embed platinum nanoparticles (Pt NPs). This nanomaterial was then tested as the counter electrode (CE) in dye-sensitized solar cells (DSSCs). SiNW/[email protected] shows potential as a good electrocatalyst based on material characterization data from Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy shows that the surface reactivity of the SiNW/C is increased by the decoration of Pt NPs. These data also show that the carbon shell included both graphitic (sp2 hybridization) and defective (sp3 hybridization) phases of carbon. We achieved the minimum charge-transfer resistance of 0.025 Ω· cm2 and the maximum efficiency of 9.46% with a symmetric dummy cell and DSSC device fabricated from the SiNW/[email protected] CEs, respectively.

ACS Style

Junhee Kim; Sanghoon Jung; Han-Jung Kim; Yoonkap Kim; Chanyong Lee; Soo Min Kim; Donghwan Kim; Yongseok Jun. SiNW/[email protected] Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells. Energies 2019, 13, 139 .

AMA Style

Junhee Kim, Sanghoon Jung, Han-Jung Kim, Yoonkap Kim, Chanyong Lee, Soo Min Kim, Donghwan Kim, Yongseok Jun. SiNW/[email protected] Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells. Energies. 2019; 13 (1):139.

Chicago/Turabian Style

Junhee Kim; Sanghoon Jung; Han-Jung Kim; Yoonkap Kim; Chanyong Lee; Soo Min Kim; Donghwan Kim; Yongseok Jun. 2019. "SiNW/[email protected] Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells." Energies 13, no. 1: 139.

Communication
Published: 20 November 2019 in Advanced Energy Materials
Reads 0
Downloads 0

Silicon solar cells among different types of solar energy harvesters have entered the commercial market owing to their high power conversion efficiency and stability. By replacing the electrode and the p‐type layer by a single layer of carbon nanotubes, the device can be further simplified. This greatly augments the attractiveness of silicon solar cells in the light of raw material shortages and the solar payback period, as well as lowering the fabrication costs. However, carbon nanotube‐based silicon solar cells still lack device efficiency and stability. These can be improved by chemical doping, antireflection coating, and encapsulation. In this work, the multifunctional effects of p‐doping, antireflection, and encapsulation are observed simultaneously, by applying a polymeric acid. This method increases the power conversion efficiency of single‐walled carbon nanotube‐based silicon solar cells from 9.5% to 14.4% and leads to unprecedented device stability of more than 120 d under severe conditions. In addition, the polymeric acid‐applied carbon nanotube‐based silicon solar cells show excellent chemical and mechanical robustness. The obtained stable efficiency stands the highest among the reported carbon nanotube‐based silicon solar cells.

ACS Style

Yang Qian; Il Jeon; Ya‐Lun Ho; Changhyun Lee; Sujeong Jeong; Clement Delacou; SeungJu Seo; Anton Anisimov; Esko I. Kaupinnen; Yutaka Matsuo; Yoonmook Kang; Hae‐Seok Lee; Donghwan Kim; Jean‐Jacques Delaunay; Shigeo Maruyama. Multifunctional Effect of p ‐Doping, Antireflection, and Encapsulation by Polymeric Acid for High Efficiency and Stable Carbon Nanotube‐Based Silicon Solar Cells. Advanced Energy Materials 2019, 10, 1 .

AMA Style

Yang Qian, Il Jeon, Ya‐Lun Ho, Changhyun Lee, Sujeong Jeong, Clement Delacou, SeungJu Seo, Anton Anisimov, Esko I. Kaupinnen, Yutaka Matsuo, Yoonmook Kang, Hae‐Seok Lee, Donghwan Kim, Jean‐Jacques Delaunay, Shigeo Maruyama. Multifunctional Effect of p ‐Doping, Antireflection, and Encapsulation by Polymeric Acid for High Efficiency and Stable Carbon Nanotube‐Based Silicon Solar Cells. Advanced Energy Materials. 2019; 10 (1):1.

Chicago/Turabian Style

Yang Qian; Il Jeon; Ya‐Lun Ho; Changhyun Lee; Sujeong Jeong; Clement Delacou; SeungJu Seo; Anton Anisimov; Esko I. Kaupinnen; Yutaka Matsuo; Yoonmook Kang; Hae‐Seok Lee; Donghwan Kim; Jean‐Jacques Delaunay; Shigeo Maruyama. 2019. "Multifunctional Effect of p ‐Doping, Antireflection, and Encapsulation by Polymeric Acid for High Efficiency and Stable Carbon Nanotube‐Based Silicon Solar Cells." Advanced Energy Materials 10, no. 1: 1.

Journal article
Published: 08 November 2019 in Thin Solid Films
Reads 0
Downloads 0

In this study, perovskite thin films (PFs) were conformally deposited on 100 cm2 textured silicon substrates using a two-step vacuum process. The PFs were fabricated by converting thin films of a sputtered-PbO precursor using the chemical vapor deposition process. The conversion of PbO thin films into PFs was confirmed by X-ray diffractometry. The uniformity of reflectance and thickness was higher than 86% and 92%, respectively, on 100 cm2 textured substrate. We applied methylammonium vapor treatment for complete conversion without residual layer and the power conversion efficiency was 10.2% on a glass/FTO/TiO2/MAPbI3/Spiro-MeOTAD/Au structure.

ACS Style

Jae-Keun Hwang; Sang-Won Lee; Wonkyu Lee; Soohyun Bae; Kyungjin Cho; Seongtak Kim; Solhee Lee; Ji Yeon Hyun; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. Conformal perovskite films on 100 cm2 textured silicon surface using two-step vacuum process. Thin Solid Films 2019, 693, 137694 .

AMA Style

Jae-Keun Hwang, Sang-Won Lee, Wonkyu Lee, Soohyun Bae, Kyungjin Cho, Seongtak Kim, Solhee Lee, Ji Yeon Hyun, Yoonmook Kang, Hae-Seok Lee, Donghwan Kim. Conformal perovskite films on 100 cm2 textured silicon surface using two-step vacuum process. Thin Solid Films. 2019; 693 ():137694.

Chicago/Turabian Style

Jae-Keun Hwang; Sang-Won Lee; Wonkyu Lee; Soohyun Bae; Kyungjin Cho; Seongtak Kim; Solhee Lee; Ji Yeon Hyun; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. 2019. "Conformal perovskite films on 100 cm2 textured silicon surface using two-step vacuum process." Thin Solid Films 693, no. : 137694.

Journal article
Published: 16 July 2019 in Sustainability
Reads 0
Downloads 0

Organic–inorganic halide perovskite solar cells (PSCs) have excellent chemical, electronic, and optical properties, making them attractive next-generation thin-film solar cells. Typical PSCs were fabricated with a perovskite absorber layer between the TiO2 electron-transport layer (ETL) and the 2,2′,7,7′-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9′-spirobifluorene (Spiro-OMeTAD) hole-transport layer (HTL). We examined the influence of phenyl-C61-butyric acid methyl ester (PCBM) on the PSC device. PSCs using the PCBM layer as an ETL were investigated, and the absorber layer was coated by dissolving PCBM in a methyl ammonium lead iodide (MAPbI3) precursor solution to examine the changes at the perovskite interface and inside the perovskite absorber layer. The PSCs fabricated by adding a small amount of PCBM to the MAPbI3 solution exhibited a significantly higher maximum efficiency of 16.55% than conventional PSCs (14.34%). Fabricating the PCBM ETL and PCBM-MAPbI3 hybrid solid is expected to be an efficient route for improving the photovoltaic performance.

ACS Style

Mijoung Kim; MoonHoe Kim; Jungseock Oh; Namhee Kwon; Yoonmook Kang; JungYup Yang. Phenyl-C61-Butyric Acid Methyl Ester Hybrid Solution for Efficient CH3NH3PbI3 Perovskite Solar Cells. Sustainability 2019, 11, 3867 .

AMA Style

Mijoung Kim, MoonHoe Kim, Jungseock Oh, Namhee Kwon, Yoonmook Kang, JungYup Yang. Phenyl-C61-Butyric Acid Methyl Ester Hybrid Solution for Efficient CH3NH3PbI3 Perovskite Solar Cells. Sustainability. 2019; 11 (14):3867.

Chicago/Turabian Style

Mijoung Kim; MoonHoe Kim; Jungseock Oh; Namhee Kwon; Yoonmook Kang; JungYup Yang. 2019. "Phenyl-C61-Butyric Acid Methyl Ester Hybrid Solution for Efficient CH3NH3PbI3 Perovskite Solar Cells." Sustainability 11, no. 14: 3867.

Journal article
Published: 10 July 2019 in Sustainability
Reads 0
Downloads 0

Al2O3/SiNx stack passivation layers are among the most popular layers used for commercial silicon solar cells. In particular, aluminum oxide has a high negative charge, while the SiNx film is known to supply hydrogen as well as impart antireflective properties. Although there are many experimental results that show that the passivation characteristics are lowered by using the stack passivation layer, the cause of the passivation is not yet understood. In this study, we investigated the passivation characteristics of Al2O3/SiNx stack layers. To identify the hydrogenation effect, we analyzed the hydrogen migration with atom probe tomography by comparing the pre-annealing and post-annealing treatments. For chemical passivation, capacitance-voltage measurements were used to confirm the negative fixed charge density due to heat treatment. Moreover, the field-effect passivation was understood by confirming changes in the Al2O3 structure using electron energy-loss spectroscopy.

ACS Style

Ji Yeon Hyun; Soohyun Bae; Yoon Chung Nam; DongKyun Kang; Sang-Won Lee; Donghwan Kim; Jooyoung Park; Yoonmook Kang; Hae-Seok Lee. Surface Passivation of Boron Emitters on n-Type Silicon Solar Cells. Sustainability 2019, 11, 3784 .

AMA Style

Ji Yeon Hyun, Soohyun Bae, Yoon Chung Nam, DongKyun Kang, Sang-Won Lee, Donghwan Kim, Jooyoung Park, Yoonmook Kang, Hae-Seok Lee. Surface Passivation of Boron Emitters on n-Type Silicon Solar Cells. Sustainability. 2019; 11 (14):3784.

Chicago/Turabian Style

Ji Yeon Hyun; Soohyun Bae; Yoon Chung Nam; DongKyun Kang; Sang-Won Lee; Donghwan Kim; Jooyoung Park; Yoonmook Kang; Hae-Seok Lee. 2019. "Surface Passivation of Boron Emitters on n-Type Silicon Solar Cells." Sustainability 11, no. 14: 3784.

Journal article
Published: 06 March 2019 in Scientific Reports
Reads 0
Downloads 0

The illuminated current-voltage characteristics of Cu(In,Ga)(S,Se)2 (CIGSSe) thin film solar cells fabricated using two different buffer layer processes: chemical bath deposition (CBD) and atomic layer deposition (ALD) were investigated. The CIGSSe solar cell with the ALD buffer showed comparable conversion efficiency to the CIGSSe solar cell with CBD buffer but lower shunt resistance even though it showed lower point shunt defect density as measured in electroluminescence. The shunt paths were investigated in detail by capturing the high-resolution dark lock-in thermography images, resolving the shunt resistance contributions of the scribing patterns (P1, P3), and depth profiling of the constituent elements. It was found that the concentration of Na from the soda-lime glass substrate played a key role in controlling the shunt paths. In the ALD process, Na segregated at the surface of CIGSSe and contributed to the increase in the shunt current through P1 and P3, resulting in a reduction in the fill factor of the CIGSSe solar cells.

ACS Style

Chan Bin Mo; Se Jin Park; Soohyun Bae; Mi-Hwa Lim; Junggyu Nam; Dongseop Kim; JungYup Yang; Dongchul Suh; Byoung Koun Min; Donghwan Kim; Yoonmook Kang; Young-Su Kim; Hae-Seok Lee. Impact of Buffer Layer Process and Na on Shunt Paths of Monolithic Series-connected CIGSSe Thin Film Solar Cells. Scientific Reports 2019, 9, 1 -11.

AMA Style

Chan Bin Mo, Se Jin Park, Soohyun Bae, Mi-Hwa Lim, Junggyu Nam, Dongseop Kim, JungYup Yang, Dongchul Suh, Byoung Koun Min, Donghwan Kim, Yoonmook Kang, Young-Su Kim, Hae-Seok Lee. Impact of Buffer Layer Process and Na on Shunt Paths of Monolithic Series-connected CIGSSe Thin Film Solar Cells. Scientific Reports. 2019; 9 (1):1-11.

Chicago/Turabian Style

Chan Bin Mo; Se Jin Park; Soohyun Bae; Mi-Hwa Lim; Junggyu Nam; Dongseop Kim; JungYup Yang; Dongchul Suh; Byoung Koun Min; Donghwan Kim; Yoonmook Kang; Young-Su Kim; Hae-Seok Lee. 2019. "Impact of Buffer Layer Process and Na on Shunt Paths of Monolithic Series-connected CIGSSe Thin Film Solar Cells." Scientific Reports 9, no. 1: 1-11.

Journal article
Published: 11 February 2019 in Thin Solid Films
Reads 0
Downloads 0

Silicon nitride (SiNx:H) films are generally used as passivation and anti-reflection layers in solar cells, and they are usually made by plasma-enhanced chemical vapor deposition (PECVD). Silicon nitride could act as a hydrogen diffusion source, and it also plays a role in chemical passivation. In this study, we investigated the improvement of the passivation characteristics of the passivated contact structure by a PECVD SiNx:H hydrogenation process and the characteristics of SiNx:H for improving the passivation characteristics. It was confirmed that the passivation characteristics cannot be predicted only by the mass density of the SiNx:H film, and the chemical bonding ratio in the SiNx:H thin film is also important. In addition, higher passivation characteristics can be obtained when SiNx:H thin films with higher SH bond concentration and dominant N2SiH2 bonds are used.

ACS Style

Jae Eun Kim; Se Jin Park; Ji Yeon Hyun; Hyomin Park; Soohyun Bae; Kwang-Sun Ji; Hyunho Kim; Kyung Dong Lee; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. Characterization of SiNx:H thin film as a hydrogen passivation layer for silicon solar cells with passivated contacts. Thin Solid Films 2019, 675, 109 -114.

AMA Style

Jae Eun Kim, Se Jin Park, Ji Yeon Hyun, Hyomin Park, Soohyun Bae, Kwang-Sun Ji, Hyunho Kim, Kyung Dong Lee, Yoonmook Kang, Hae-Seok Lee, Donghwan Kim. Characterization of SiNx:H thin film as a hydrogen passivation layer for silicon solar cells with passivated contacts. Thin Solid Films. 2019; 675 ():109-114.

Chicago/Turabian Style

Jae Eun Kim; Se Jin Park; Ji Yeon Hyun; Hyomin Park; Soohyun Bae; Kwang-Sun Ji; Hyunho Kim; Kyung Dong Lee; Yoonmook Kang; Hae-Seok Lee; Donghwan Kim. 2019. "Characterization of SiNx:H thin film as a hydrogen passivation layer for silicon solar cells with passivated contacts." Thin Solid Films 675, no. : 109-114.

Journal article
Published: 18 December 2018 in ECS Journal of Solid State Science and Technology
Reads 0
Downloads 0

Commercializing a highly efficient passivated-emitter-and-rear-cell solar cell requires high passivation quality and stability of the cell's Al2O3 layer. This paper reports on light-induced degradation (LID) of the Al2O3 layer and the effects of post-annealing temperatures after light soaking on the passivation quality. To understand the LID phenomenon of the Al2O3 passivation layer, we used a Ga-doped Si wafer that prevented boron-oxygen LID effects. The fabrication process was carried out on large-area (156 × 156 mm2), commercially available, (100)-oriented Ga-doped Czochralski(Cz) Si wafers in the pilot line. Before and after light soaking, the effective lifetime was measured using Sinton's quasi-steady-state photoconductance as a function of annealing temperature. Chemical binding structures near the interface of the Al2O3 film and Si wafer were investigated using X-ray photoelectron spectroscopy (XPS). The passivation quality and light-induced degradation showed the best performance at an annealing temperature of 600°C. Analysis of XPS data revealed that the chemical binding structures at the interface of the Al2O3 layer and Si wafer were stabilized by optimizing the annealing condition of the Al2O3 layer. By optimizing an industrially feasible Al2O3 passivation process, an efficiency of 20.1% was achieved on large-area, commercial-grade Cz c-Si wafers.

ACS Style

Chan Bin Mo; Sungeun Park; Soohyun Bae; Se Jin Park; Young-Su Kim; JungYup Yang; Hyunjong Kim; Dongchul Suh; Yoonmook Kang. Minimizing Light-Induced Degradation of the Al2O3Rear Passivation Layer for Highly Efficient PERC Solar Cells. ECS Journal of Solid State Science and Technology 2018, 7, Q253 -Q258.

AMA Style

Chan Bin Mo, Sungeun Park, Soohyun Bae, Se Jin Park, Young-Su Kim, JungYup Yang, Hyunjong Kim, Dongchul Suh, Yoonmook Kang. Minimizing Light-Induced Degradation of the Al2O3Rear Passivation Layer for Highly Efficient PERC Solar Cells. ECS Journal of Solid State Science and Technology. 2018; 7 (12):Q253-Q258.

Chicago/Turabian Style

Chan Bin Mo; Sungeun Park; Soohyun Bae; Se Jin Park; Young-Su Kim; JungYup Yang; Hyunjong Kim; Dongchul Suh; Yoonmook Kang. 2018. "Minimizing Light-Induced Degradation of the Al2O3Rear Passivation Layer for Highly Efficient PERC Solar Cells." ECS Journal of Solid State Science and Technology 7, no. 12: Q253-Q258.

Journal article
Published: 22 November 2018 in Energies
Reads 0
Downloads 0

In this study, we developed a finite element model to assess the residual stress in the soldering and lamination processes during the fabrication of crystalline silicon (Si) photovoltaic (PV) modules. We found that Si wafers experience maximum thermo-mechanical stress during the soldering process. Then, the Si solar cells experience pressure during the process of lamination of each layer of the PV module. Thus, it is important to decrease the residual stress during soldering of thin Si wafers. The residual stress is affected by the number of busbars, Si wafer thickness, and solder type. Firstly, as the number of busbars increases from two to twelve, the maximum principal stress increases by almost a factor of three (~100 MPa). Such a high first principal stress can cause mechanical failure in some Si wafers. Secondly, thermal warpage increases immediately after the soldering process when the thickness of the Si wafers decreases. Therefore, the number and width of the busbars should be considered in order to avoid mechanical failure. Finally, the residual stress can be reduced by using low melting point solder. The results obtained in this study can be applied to avoid mechanical failure in PV modules employing thin Si wafers.

ACS Style

Hyunseong Shin; Ekyu Han; Nochang Park; Donghwan Kim. Thermal Residual Stress Analysis of Soldering and Lamination Processes for Fabrication of Crystalline Silicon Photovoltaic Modules. Energies 2018, 11, 3256 .

AMA Style

Hyunseong Shin, Ekyu Han, Nochang Park, Donghwan Kim. Thermal Residual Stress Analysis of Soldering and Lamination Processes for Fabrication of Crystalline Silicon Photovoltaic Modules. Energies. 2018; 11 (12):3256.

Chicago/Turabian Style

Hyunseong Shin; Ekyu Han; Nochang Park; Donghwan Kim. 2018. "Thermal Residual Stress Analysis of Soldering and Lamination Processes for Fabrication of Crystalline Silicon Photovoltaic Modules." Energies 11, no. 12: 3256.