Affiliation:
1. Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information (SOEI) Huazhong University of Science and Technology Wuhan Hubei 430074 China
2. Optics Valley Laboratory Wuhan Hubei 430074 China
Abstract
Large‐scale all‐perovskite tandem photovoltaic has raised more attention as the power conversion efficiency (PCE) of this device in a small area reaches 28%. However, the wide‐bandgap (WBG)‐perovskite (Cs0.2FA0.8Pb(I0.6Br0.4)3‐1.77 eV) fabrication on a large scale still faces difficulty in nucleation and crystallization control, leading to complicated intermediates and poor‐quality films. Through a systematic investigation of the vacuum‐assisted blade‐coated WBG perovskite film formation process, the origin for poor film quality is attributed to the numerous nucleation pathways under rapid vacuum pressure decrease, resulting in a mix in intermediates of (Cs,FA)2Pb3(I,Br)8·xNMP, δ‐FAPbI3·xNMP, and PbI2·xNMP. To solve this problem, a proper additive MACl is selected and added. By lowering the formation energy of intermediate ((Cs,FA)Pb(I,Br)3·MACl·xNMP), the nucleation and crystallization process is successfully modulated into a single way, resulting in a single‐orientation (100) film and an enhanced device performance of 16.75%, which is the champion PCE of blade‐coated 1.77 eV perovskite so far.
Funder
Fundamental Research Funds for the Central Universities
China Postdoctoral Science Foundation
National Natural Science Foundation of China
Subject
Electrical and Electronic Engineering,Energy Engineering and Power Technology,Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials