ZnO electron transporting layer engineering realized over 20% efficiency and over 1.28 V open‐circuit voltage in all‐inorganic perovskite solar cells. Issue 4 (25th February 2022)

• Record Type: Journal Article
• Authors: Wu, Xiao; Zhang, Jianquan; Qin, Minchao; Liu, Kuan; Lv, Ziyu; Qin, Zhaotong; Guo, Xinlu; Li, Yuhao; Xu, Jianbin; Li, Gang; Yan, He; Lu, Xinhui
• Is Part Of: EcoMat. Volume 4:Issue 4(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-02-25
• Subjects: all‐inorganic -- energy level -- oxygen vacancy -- perovskite solar cells -- ZnO; Materials -- Environmental aspects -- Periodicals; Clean energy -- Periodicals; 621.042
• DOI: 10.1002/eom2.12192
• Languages: English
• ISSNs: 2567-3173

Abstract

Abstract: Cesium lead based all‐inorganic perovskite solar cells (PSCs) are promising candidates for tandem solar cells owing to their favorable thermal stability and suitable bandgap. However, to exploit the advantage to the full, there is still huge room to reduce energy loss and enhance the V OC . In this work, we developed low‐temperature processed ZnO as an ETL alternative. Incorporation of PbX2 (X = I −, Cl −, and CH3 COO − ) was found to increase oxygen vacancies in ZnO, which not only promoted the growth of all‐inorganic perovskite layer with improved morphology and orientational order, but also formed a favorable energy level alignment with the perovskite layer, thus facilitating charge extraction and suppressing charge recombination. Consequently, the CsPb(I1− x Br x )3 PSCs based on PbX2 :ZnO exhibited enhanced stability and performance. The efficiency was boosted from 17.64% to 20.04% with an improved fill factor of 84.14% and a V OC of 1.28 V, being the highest V OC among highly efficient (>20%) all‐inorganic PSCs to date. Abstract : Low‐temperature processed electron transporting layer ZnO was modified by Pb(II) salts to regulate the concentration of oxygen vacancy thus promoting the morphological and electrical properties of ZnO, and the orientational order of the perovskite on top. The charge extraction/recombination was improved, boosting the open‐circuit voltage to 1.28 V with an efficiency of 20.04% in all‐inorganic perovskite solar cells.