Insights from Theoretical Modeling of Cesium-Formamidinium-Based Mixed-Halide Perovskite Solar Cells for Outdoor and Indoor Applications

This study presents an in-depth computational analysis of hybrid organic-inorganic lead halide perovskite solar cells (PSCs) with a composition of Cs_0.17FA_0.83Pb(Br_0.4I_0.6)₃ (FA: formamidinium) material under cool and warm light-emitting diodes (LEDs). We propose a novel design of an inverted (<i>p</i>-<i>i</i>-<i>n</i>) PSC to compare the power conversion efficiencies (PCEs) of opaque and semitransparent models under the AM1.5G spectrum and indoor LED lighting. The Shockley-Queisser (SQ) limits were estimated for LEDs with color temperatures of 3000 and 6000 K, revealing significant differences in PCE compared to standard solar radiation. The optical and electrical properties of the perovskite devices were simulated by using the transfer-matrix method and one-dimensional drift-diffusion model. We report a PCE of 15.8% for opaque devices under the AM1.5G spectrum, while the semitransparent devices exhibit PCEs of 12.07% and 10.17% for front and rear illumination, respectively. Under indoor conditions with cool LED lighting, the opaque devices demonstrate a significantly higher PCE of 28.38% and an impressive photovoltage of 1.17 V, surpassing the semitransparent devices, which show efficiencies of approximately 19.5% (front illumination) and 18.3% (rear illumination). While the interface between the hole transport layer and perovskite has a major impact on the device performance of opaque solar cells, the perovskite/electron transport layer junction plays a more critical role in the performance of semitransparent solar cells. The power densities for opaque devices reached up to 106.25 μW/cm² under cool LED and 97.1 μW/cm² with warm LED illumination. For semitransparent devices, the power densities exceeded 60.71 μW/cm² on front-side illumination and 73.66 μW/cm² on rear illumination under cool LEDs. These results emphasize the significant potential of hybrid PSCs for efficient energy harvesting under various lighting conditions, making them promising candidates for powering low-energy-consumption electronics in indoor environments.