${Cu}_2\mathit{\text{ZnSn}}{S}_4(\mathit{\text{CZTS}})$ is a non-toxic earth abundant material and a promising quaternary semiconductor compound of groups $I-II-IV-VI$ having a kesterite symmetrical structure. Due to its optimum direct bandgap, it has been considered as a suitable material for absorber layers for photovoltaic cell applications. This paper presents the numerical simulation and modeling of $\mathit{\text{CZTS}}$ based thin film kesterite photovoltaic cells using SCAP-1D software. The influence of device parameters such as the carrier concentration, thickness, densities of absorber, buffer and window layers, defect densities and the temperature effect on the performance of the $ZnO/CdS/\mathit{\text{CZTS}}/Mo$ photovoltaic cell structure are analyzed. Defect densities are added to the absorber layer and the interface between the buffer layer and the absorber layer. This type of solar cell does not comprise any toxic material and can lead to non-toxic thin film photovoltaic cells with outstanding optical properties. In this work, promising optimized results had been achieved with a conversion efficiency of 23.72%, a fill factor of 82.54%, a short-circuit current ($J_{sc})$ of 44.87 ${\text{mA}/\text{cm}}^2$ , and an open circuit voltage ${(V}_{oc})$ of 0.64V.

In this paper we proposed a solar cell having model “Back Contact/CZTS/ZnCdS/ZnO/Front Contact”. CZTS is working as an absorber layer, ZnCdS as a buffer layer and ZnO as a window layer with back and front contacts. The Zn content was varied from 0% to 10% and bad gap was changed from 2.42 to 2.90 eV as described in the literature. The impact of this band gap variation has been observed on the performance of solar cell by using SCAPS-1D software. The efficiency was varied due to variation in bandgap of ZnCdS thin film layer. The simulation was carried out at 300K under A.M 1.5 G 1 Sun illumination. The energy bandgap diagram has been taken from SCAPS to explain the different parameters of solar cell. The effect of ZnCdS having different bandgap values was observed. Then the thickness of CZTS layer was varied to check its effect and hence at 3.0 um gave the imporved efficiency of 13.83% roundabout. After optimization of CZTS layer thickness, the effect of working temperature was examined on the performance of solar cell. The absorption coefficient variation from 1E+4 to 1E+9 cm-1 caused major effects on the characteristics parameters of solar cell along with on J-V characteristics and Quantum Efficiency curve. At 1E+9 cm-1 absorption coefficient the efficiency of solar cell boost up to 16.24%. This is the remarkable improvement in the efficiency of solar cell from 13.82% to 16.24%. After optimization of all parameters, simulation was run at 280K, having CZTS thickness of 3.5 um, with 10% content Zn in ZnCdS (2.90 eV), and absoption coefficient of 1E+9, the model efficiency reached up to 17.6% with Voc of 0.994 V, Jsc 26.1 mA/cm2 and Fill factor was 71.4%.

In this research work, the electrical simulation of 1D5P model solar cell is done using LTSpice-IV simulation software. In this work effect of environmental conditions i.e temperature, solar irradiance, and parasitic parameters i.e series as well as shunt resistances was carried out. It has been discovered that as temperature increases the performance of solar cell decrease because temperature causes to increase the recombination phenomenon and hence lower the performance. However, when the temperature rises from 00C to 500C, the I-V and P-V curves move to the origin showing the negative effect of increasing temperature on the solar cell. Solar irradiance has major role on the performance of solar cell. As solar irradiance increases from 250 Wm-2 to 1000 Wm-2, the performance of solar cell increases accordingly and I-V as well as P-V curve moves away from the origin. It is concluded that for different series resistances, I-V along with P-V characteristic of 1D5P model solar cell varies, as at 0.02Ω series resistance, a maximum short circuit current and maximum power is obtained. But when series resistance increased up 2 ohm only, the I-V and P-V curves moves to origin drastically. Shunt Resistance is the path of reverse current of the cell. As the shunt resistance increases, the path for reverse current decreased, hence all current goes to load, hence maximum power is obtained. Similarly when the value of shunt resistance decreased, the voltage-controlled section of I-V characteristics curve is moved closer to the origin hence reduced the solar cell performance. It's critical to understand how different factors affect the I-V and P-V characteristics curves of solar cells. The open circuit voltage, short circuit current and maximum power is all variable. The influence of these factors may be extremely beneficial when tracking highest power point of a solar cell applying various methods.

Recent developments based on lead (Pb) halide perovskites have inspired extensive research into low-cost solar cells in attempt to overcome the primary issues such as stability and toxicity that occur in this area. Solar cell simulation of lead-free perovskite (CH₃NH₃SnBr₃) as an absorber-based solar cell was performed using SCAPS-1D simulation tool in this work. An impact of absorber layer thickness and working temperature on photovoltaic characteristics of CH₃NH₃SnBr₃-based perovskite solar cells was investigated using numerical modeling techniques. The thickness was varied from 1.0 μm to 3.0 μm, and working temperature was varied from 290 K to 330 K, and their effect was examined on the photovoltaic parameters of proposed “Back Contact/CH₃NH₃SnBr₃/CdS/ZnO/Front Contact” solar cell. The improvement in the efficiency of solar cell by optimization of CH₃NH₃SnBr₃ absorber layer thickness and working temperature was observed.

Renewable energy resources are being used to overcome energy shortage. From the point of view of energy management the interconnectivity of electric utility with renewable energy resources is difficult. Renewable energy resources need to be managed with electric utility. A Smart Energy Management System (SEMS) is designed and developed for monitoring an efficient load management of electric utility and photovoltaic power system is presented in this research. The design consists of an Energy Management Center (EMC) and Field Programmable Gate Array (FPGA). Energy Management Center shows the runtime data and also keeps the data log and offers control of the load shifting between utility source and photovoltaic power system. Analog to digital converter is used to interface the current and voltage sensors with FPGA. ZigBee is connected for wireless radio data transmission between the FPGA and energy management & monitoring center. The SEMS increases the efficiency of energy up to 10.5 percent in comparison with normal systems.