A multifunctional additive for enhancing the performance of single-junction perovskite and perovskite/silicon tandem solar cells

Abstract

In recent years, perovskite/silicon tandem solar cells have emerged as a research hotspot in the field of solar cells. For high-efficiency tandem solar cells, the crystallinity and defect control of the wide-bandgap perovskite absorber layer are crucial. Herein, FA_0.8Cs_0.2Pb(I_0.8Br_0.2)₃ wide-bandgap perovskite films with a bandgap of 1.67 eV are developed using phthalic anhydride-tert-butyloxycarbonyl (BD-Boc) as an additive. The resulting films exhibit improved quality, enhanced crystallinity, reduced bulk defects, improved phase stability, and reduced residual surface stress. Time-resolved photoluminescence (TRPL) and photoluminescence (PL) analysis revealed that the films exhibit low non-radiative recombination (NRR) losses and a high average carrier lifetime. Based on the above FA_0.8Cs_0.2Pb(I_0.8Br_0.2)₃ perovskite thin film modified with BD-Boc, the wide-bandgap single-junction perovskite solar cells achieved a champion power conversion efficiency (PCE) of 22.92%, an open-circuit voltage of 1.22 V, and a fill factor of 83.47%. Furthermore, using the BD-Boc-modified wide-bandgap perovskite single-junction cell as the top subcell, a perovskite/crystalline silicon tandem solar cell with a designated active area of 1 cm² was fabricated, which achieves a PCE of 28.47%.