Enhanced Interfacial Binding and Electron Extraction Using Boron‐Doped TiO2 for Highly Efficient Hysteresis‐Free Perovskite Solar Cells

Advanced Science

Jihuai Wu¹  Mohammad Khaja Nazeeruddin²  Linhua Hu³  Xiaoqiang Shi⁴  Molang Cai⁴  Bing Zhang⁴  Jianxi Yao⁴  Songyuan Dai⁴  Shijie Zhou⁴  Yong Ding⁴ 

[1] Fujian Provincial Key Laboratory of Photoelectric Functional Materials Institute of Materials Physical Chemistry Huaqiao University Xiamen 361021 P. R. China;Group for Molecular Engineering of Functional Materials Institute of Chemical Sciences and Engineering École Polytechnique Fédérale de Lausanne CH‐1951 Sion Switzerland;Key Laboratory of Photovoltaic and Energy Conservation Materials Institute of Applied Technology Hefei Institutes of Physical Science Chinese Academy of Sciences Hefei 230031 Anhui P. R. China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 P. R. China;

关键词: charge transport;    hysteresis;    interfacial binding;    perovskite solar cells;    titanium dioxide;   

DOI  :  10.1002/advs.201901213

来源: DOAJ

【 摘 要 】

Abstract Perovskite solar cells (PSCs) have witnessed astonishing improvement in power conversion efficiency (PCE), more recently, with advances in long‐term stability and scalable fabrication. However, the presence of an anomalous hysteresis behavior in the current density–voltage characteristic of these devices remains a key obstacle on the road to commercialization. Herein, sol–gel‐processed mesoporous boron‐doped TiO2 (B‐TiO2) is demonstrated as an improved electron transport layer (ETL) for PSCs for the reduction of hysteresis. The incorporation of boron dopant in TiO2 ETL not only reduces the hysteresis behavior but also improves PCE of the perovskite device. The simultaneous improvements are mainly ascribed to the following two reasons. First, the substitution of under‐coordinated titanium atom by boron species effectively passivates oxygen vacancy defects in the TiO2 ETL, leading to increased electron mobility and conductivity, thereby greatly facilitating electron transport. Second, the boron dopant upshifts the conduction band edge of TiO2, resulting in more efficient electron extraction with suppressed charge recombination. Consequently, a methylammonium lead iodide (MAPbI3) photovoltaic device based on B‐TiO2 ETL achieves a higher efficiency of 20.51% than the 19.06% of the pure TiO2 ETL based device, and the hysteresis is reduced from 0.13% to 0.01% with the B‐TiO2 based device showing negligible hysteresis behavior.

【 授权许可】

Unknown