Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
DOI: https://doi.org/10.29363/nanoge.hopv.2022.175
Publication date: 20th April 2022
Bandgaps (Eg) of perovskite materials can be readily tuned by chemical composition. Here, by substituting iodine with bromine from 0 to 100% (Br0 to Br1), we linked photovoltaic (PV) performance not only to Eg which varied from 1.5 to 2.3 eV but also, crucially, to film morphological and properties under both standard test conditions (STC) and indoor conditions. A linear dependence of Eg with Br− content (x) (Eg=0.75x+1.48 eV) translated in a monotonic increase in Voc and a corresponding decrease in Jsc under STC. Under indoor illumination similar smooth trends were not observed, which is due to perovskite films quality have a strong bearing on cell performance, especially at low light levels. Br content of 17% (Eg = 1.61 eV) delivered the highest PCE of 22.01% and 27.09% at 200 and 1000 lx, respectively due to the films possessing the largest shunt resistance (10.04 KΩ·cm2) and JON/JOFF current ratio (6.9×102) rather than the best theoretical gap. Importantly, we extended systematic study to stability and found that the same perovskite film was the most stable, indicating that the morphology of perovskite films influences not only PCE but also long-term performance. Our thorough investigation, and identification of key parameters including resistance and JON/JOFF current ratios, paves a way for achieving high-performance indoor photovoltaics.
JX gratefully acknowledges financial support from the China Scholarship Council (CSC, No.202004910288). The project has received funding from Lazio Region through ISIS@MACH (IR approved by Giunta Regionale n. G10795, 7 August 2019 published by BURL n. 69 27 August 2019), and the Italian Ministry of University and Research (MIUR) through the PRIN2017 BOOSTER (project n.2017YXX8AZ) grant.