Cost-Effective High-Performance Charge-Carrier-Transport-Layer-Free Perovskite Solar Cells Achieved by Suppressing Ion Migration
Tao Ye, Yu Hou, Amin Nozariasbmarz, Dong Yang, Jungjin Yoon, Luyao Zheng, Ke Wang, Ke Wang, Kai Wang, Kai Wang, Seeram Ramakrishna, Shashank Priya
Abstract
Perovskite solar cells (PSCs) without charge-carrier-transport layers (CTLs) are theoretically achievable due to the ambipolar charge-carrier-transfer characteristics presenting in perovskites. However, the power conversion efficiency (PCE) of the CTL-free PSCs needs further improvement. Herein, we provide a breakthrough in the fabrication of the cost-effective high-performance hole-transport-layer (HTL)-free PSC and trilayer PSC with device configurations of fluorine doped tin oxide (FTO)/SnO2/perovskite/carbon and FTO/perovskite/carbon, respectively. We introduce perfluorotetradecanoic acid (PFTeDA) with a carbonyl unit and carbon fluorine bonds to suppress the ion migration and reduce the crystal defects in perovskites. The modified carbon-based HTL-free PSC shows a record PCE of 18.9%. Furthermore, the PFTeDA molecules are found existing at the grain boundaries between the perovskite crystals, resulting in enhanced environmental, thermal, and light stabilities for the resultant cost-effective high-performance CTL-free PSCs.