Inorganic Lead‐Free Cs₂AuBiCl₆ Perovskite Absorber and Cu₂O Hole Transport Material Based Single‐Junction Solar Cells with 22.18% Power Conversion Efficiency

Abstract

Cs2AuBiCl6 is considered to be a potential lead‐free double perovskite alternative for perovskite solar cells. Its electronic and optical properties are investigated using density functional theory. The electronic properties of Cs2AuBiCl6 material ensure a bandgap of 1.40 eV (without considering SOC) and 1.12 eV (with SOC) using mBJ exchange‐correlation functional, close to the optimal bandgap for solar cell application as per the Shockley–Queisser limit. Optical properties suggest a high absorption coefficient ≈105 cm−1 with low reflectance, making it the optimal absorber material. Furthermore, the photovoltaic performance of Cs2AuBiCl6 based single‐junction transparent conducting oxide (TCO)/IDL1/Cs2AuBiCl6/IDL2/Cu2O solar cell is investigated using SCAPS‐1D device simulation program. The impact of electron affinity, thickness, carrier concentration, defect density, and interface defect density is examined using interface defect layer (IDL) on the photovoltaic performance. The maximum photoconversion efficiency (PCE) of ≈22.18% is noticed for optimized material's parameters. These studies on TCO/IDL1/Cs2AuBiCl6/IDL2/Cu2O solar cell will provide guidelines for designing and developing an efficient lead‐free perovskite‐based solar cell as an alternative to conventional halide perovskite materials based solar cell.

Lead‐Free Double Perovskite Cs2AgBiBr6: Fundamentals, Applications, and Perspectives

“…Using Au + /Au 3+ to substitute Ag + /Bi 3+ can form stable Cs 2 AuBiCl 6 (1.4 eV indirect bandgap) and Cs 2 AgAuI 6 (1.289 eV direct bandgap) perovskites with low hole/electron effective masses, which are worthy of further experimental research. [194,195] Similar interesting lead-free halides such as Cu 2 AgBiI 6 have emerged as promising solar cell absorbers with a direct bandgap of 2.06 eV, even if it is not a perovskite. [196,197] Low-dimensional Cs 2 AgBiBr 6 derivatives also offer the possibility to transform indirect to direct bandgap and change the optoelectronic properties.…”

Thin‐Film Solar Cells by Silicon‐Based Nano‐Pyramid Arrays

“…Among all kinds of new clean energy, solar energy is considered to be one of the most promising clean energy sources. [1][2][3][4][5][6] Photovoltaic conversion is an important way to convert solar energy into electricity based on light trapping effect. [7][8][9][10][11] However, crystalline silicon (c-Si) solar cells have low absorption of photons near the bandgap.…”

First‐principles investigation of Rb2Ag(Ga/In)Br6 for thermoelectric and photovoltaic applications

“…In addition, they have excellent optoelectronic properties such as high optical absorption, appreciable optical conductivity, large dielectric constant, and long carrier lifetime. To date, many lead‐free double halide perovskites have been explored for energy applications [13–17]. But, most of them are either not stable or do not have suitable electronic and optical properties.…”