Room temperature (RT) synthesis of the ternary cesium lead bromide CsPbBr₃ quantum dots with oleic acid and oleylamine ligands was developed by Zeng and coworkers in 2016. In their works, the supersaturated recrystallization (SR) was adopted as a processing method without requiring inert gas and high-temperature injection. However, the oleic acid ligand for haloplumbate is known to be relatively unstable. Hence, in this work, we employed the eco-friendly olive oil to replace the oleic acid portion for the SR process at RT. Resultantly, we found that the cube-shaped nanocrystal has a size of ~40–42 nm and an optical bandgap of ~2.3 eV independent of the surface ligands, but the photoluminescence lifetime (τ_av) and crystal packing are dependent on the ligand species, e.g., τ_av = 3.228 ns (olive oil and oleylamine; here less ordered) vs. 1.167 ns (oleic acid and oleylamine). Importantly, we explain the SR mechanism from the viewpoint of the classical LaMer model combined with the solvent engineering technique in details.

Perovskite solar cells (PSCs) have garnered extensive research interest due to their potential for efficient, flexible, and cost-effective solar energy production, making them suitable for wearable and low-cost applications. In this study, we successfully synthesized layered copper-based perovskite materials, and subsequently conducted simulations using the Solar Cell Capacitance Simulator SCAPS-1D. This study introduces, a PSC structure with (CH₃NH₃)₂CuCl₄ as the active layer. By employing a two-step chemical method, we have successfully synthesized (CH₃NH₃)₂CuCl₄, and its optical band gap was determined using Tauc’s extrapolation method. Utilizing the experimentally determined bandgap as the simulation input, we predicted a solar architecture consisting of glass substrate/fluorine-doped tin oxide/TiO₂/(CH₃NH₃)₂CuCl₄/spiro-OMeTAD/Pt, which exhibited an impressive conversion efficiency of 27.93% along with a fill factor of 62.04%, J _sc of 34.39 mA cm⁻², and V _oc of 1.31 V. Through the software, we conducted a comprehensive study on the impact of back metal contact, hole transport layer, electron transport layer, layer thickness, temperature, and defect density on the overall device performance. These results unveil the development of an environmentally friendly PSC based on methylammonium copper.

Recently, tuning the green emission of CsPbBr₃ quantum dots (QDs) to blue through quantum size and confinement effects has received considerable attention due to its remarkable photophysical properties. However, the synthesis of such a blue-emitting QD has been challenging. Herein, supersaturated recrystallization was successfully implemented at room temperature to synthesize a broadband blue-emitting ZnBr₂-doped CsPbBr₃ QD with an average size of ~3 nm covering the blue spectrum. The structural and optical properties of CsPbBr₃ QDs demonstrated that QD particle size may decrease by accommodating ZnBr₂ dopants into the perovskite precursor solution. Energy-dispersive spectroscopy confirmed the presence of zinc ions with the QDs. This work provides a new strategy for synthesizing strongly quantum-confined QD materials for photonic devices such as light-emitting diodes and lighting.

The phase change of all-inorganic cesium lead halide (CsPbI₃) thin film from yellow δ-phase to black γ-/α-phase has been a topic of interest in the perovskite optoelectronics field. Here, the main focus is how to secure a black perovskite phase by avoiding a yellow one. In this work, we fabricated a self-doped CsPbI₃ thin film by incorporating an excess cesium iodide (CsI) into the perovskite precursor solution. Then, we studied the effect of organic additive such as 1,8-diiodooctane (DIO), 1-chloronaphthalene (CN), and 1,8-octanedithiol (ODT) on the optical, structural, and morphological properties. Specifically, for elucidating the binary additive–solvent solution thermodynamics, we employed the Flory–Huggins theory based on the oligomer level of additives’ molar mass. Resultantly, we found that the miscibility of additive–solvent displaying an upper critical solution temperature (UCST) behavior is in the sequence CN:DMF > ODT:DMF > DIO:DMF, the trends of which could be similarly applied to DMSO. Finally, the self-doping strategy with additive engineering should help fabricate a black γ-phase perovskite although the mixed phases of δ-CsPbI₃, γ-CsPbI₃, and Cs₄PbI₆ were observed under ambient conditions. However, the results may provide insight for the stability of metastable γ-phase CsPbI₃ at room temperature.

This work presents a SCAPS-1D simulation based design for PSC with cesium silver bismuth bromide (Cs ₂ AgBiBr ₆ ) absorber layer and tries to find out the best possible combination of charge transport layers and optimum values of physical parameters which can point out the right direction towards an actual laboratory synthesis of perovskite solar cells with the most efficient configuration. The work also explores the properties of the optimized design by analyzing both its DC response through JV characteristics and AC response through Mott Schottky and Nyquist plots. The quantum efficiency profile is also plotted to understand the photon to exciton conversion efficiency at different regions of electromagnetic spectrum. This work suggests the structure ITO/C ₆₀ /Cs ₂ AgBiBr ₆ /SpiroOMeTAD/Au as a feasible combination of solar cell with lead free double perovskite absorber layer, after analyzing the effect of different charge transport layers. The work also determines the optimum thickness for HTL, ETL and absorber layer involved in the structure and the maximum efficiency is found to be 7.4%. The effect of temperature and total defect density in the power conversion efficiency of the solar cells is studied. The AC simulations of the optimized configuration is carried out by obtaining Mott Schottky and Nyquist plots. The quantum efficiency profile is also determined predicting good absorption in the UV, blue and green region of electromagnetic spectrum. Further the effect of incorporating CdS as an electron extractor in the structure is analyzed to find out theoretically how far the efficiency can be improved in spite of its toxicity. The work also shows how interfacial defect density becomes a major factor limiting the power conversion efficiency of Cs ₂ AgBiBr ₆ double perovskite solar cells.