Yttrium‐doped<scp>Sn<sub>3</sub>O<sub>4</sub>two‐dimensional</scp>electron transport material for perovskite solar cells with efficiency over 23%
Sheng Li, Jiale Liu, Shuang Liu, Deyi Zhang, Chao Liu, Daiyu Li, Jianhang Qi, Yue Hu, Anyi Mei, Hongwei Han
Abstract
Abstract The two‐dimensional mixed‐valence tin oxide Sn 3 O 4 with a low defect density of states and suitable energy band structure has shown great potential as the electron transport layer (ETL) for perovskite solar cells (PSCs). However, the electron density of Sn 3 O 4 is low and should be modulated to demonstrate its application for more efficient PSCs. Here, Sn 3 O 4 is doped with yttrium (Y) to optimize its electronic properties and improve the performance of PSCs based on Sn 3 O 4 ETL. The conductivity of Sn 3 O 4 is improved from 6.6 × 10 −4 to 2.05 × 10 −3 S m −1 with increased electron density by Y doping. Meanwhile, the Fermi level of Sn 3 O 4 is also upshifted after doping. The increased electron density and upshifted Fermi level enhance the electron extraction capability of Sn 3 O 4 and built‐in potential in PSCs. By doping the Sn 3 O 4 ETL with Y, the power conversion efficiency of PSCs is successfully boosted to 23.05%. image