Vacuum-Controlled Growth of CsPbI2Br for Highly Efficient and Stable All-Inorganic Perovskite Solar Cells

Tianyi Wang; Yifan Yang; Yu Zhang; Li Nian; Peng Wang; Yinping Qian; Qikun Rong; Guofu Zhou; Na Li

doi:10.1021/acsami.0c01583

Vacuum-Controlled Growth of CsPbI₂Br for Highly Efficient and Stable All-Inorganic Perovskite Solar Cells

ACS Appl Mater Interfaces. 2020 May 13;12(19):21539-21547. doi: 10.1021/acsami.0c01583. Epub 2020 Apr 30.

Authors

Tianyi Wang^{1

2}, Yifan Yang^{1

2}, Yu Zhang^{1

2}, Li Nian^{1

2}, Peng Wang^{1

2}, Yinping Qian^{1

2}, Qikun Rong^{1

2}, Guofu Zhou^{1

2}, Na Li^{1

3}

Affiliations

¹ Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
² National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China.
³ School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China.

PMID: 32301605
DOI: 10.1021/acsami.0c01583

Abstract

A high-temperature annealing process (>250 °C) is always needed to obtain high-quality α-CsPbI₂Br perovskite films, which makes it a challenge in the manufacture and application of flexible photovoltaic devices. In this work, a vacuum-controlled growth (VCG) method that can effectively control the crystallization of perovskite and provide high-quality films with larger grain size and low defect density at a lower temperature is demonstrated. Besides, a facile introduction of polyethyleneimine ethoxylated (PEIE) interlayer improves the charge extraction and suppresses the carrier recombination. Therefore, the power conversion efficiency (PCE) of an all-inorganic CsPbI₂Br perovskite solar cell (PSC) reaches 12.32%. The unencapsulated PSCs with VCG treatment and PEIE modification show outstanding stabilities while retaining over 95% of the initial PCE after being stored in a N₂ glovebox for 1000 h. This low-temperature crystallization method and cheap interlayer introduction can drive the development of future commercialization of all-inorganic perovskite solar cells.

Keywords: all-inorganic perovskite solar cells; crystallization control; film fabrication; interface modification; low temperature; vacuum-controlled growth.