Insights into the potential of Sb alloyed Cu2AgBiI6-based solar cells: For efficient indoor energy-harvesting

Abstract

Recently, indoor photovoltaics have attracted significant attention due to their remarkable capability to generate power from indoor light sources. This work investigates the performance of perovskite-inspired material Sb alloyed Cu<inf>2</inf>AgBiI<inf>6</inf> (CABI-Sb) based indoor photovoltaic device, which has shown a power conversion efficiency of 9.53 %, reported in a recent experimental study by B. Al-Anesi et al. The baseline model of the CABI-Sb device structure (FTO/TiO<inf>2</inf>/CABI-Sb/Spiro-OMeTAD/Au) is developed in SCAPS-1D using the earlier reported experimental data. Baseline model parameters under WLED illumination are Jsc: 128.2 µA/cm2, Voc: 0.51 V, FF: 66.57 %, and PCE: 9.53 %, with a minor deviation of less than 1 %, which validates the developed model with experimental data. The performance of the device is fine-tuned by optimizing 1) Absorber thickness and defect density 2) Electron Transport Layer (ETL) doping density, conduction band offset (CBO) and interface defect density between the ETL/absorber (TiO<inf>2</inf> /CABI-Sb) interface, 3) Hole Transport Layer (HTL) doping density, valence band offset (VBO) and interface defect density between HTL/absorber (CABI-Sb/Spiro-OMeTAD) interface, 4) work function of contacts, and 5) Series and shunt resistance were optimized. The performance parameters of the optimized device under the WLED illumination are Jsc: 1.84 mA/cm2, Voc: 1.60 V, FF: 86.78 %, and PCE: 49.31 %. A remarkable improvement in PCE is achieved from 9.53 % to 49.31 %. Further, to validate the suitability of the optimized device under different indoor environments, optimized device performance is evaluated under different lux intensities of WLED (6500 K), WLED (2700 K), compact fluorescent light (CFL), and halogen. © 2024 International Solar Energy Society