Over 16% Efficient Solution‐Processed Cu(In, Ga)Se2 Solar Cells via Incorporation of Copper‐Rich Precursor Film. Issue 39 (26th August 2022)

• Record Type: Journal Article
• Authors: Gao, Qianqian; Yuan, Shengjie; Zhou, Zhengji; Kou, Dongxing; Zhou, Wenhui; Meng, Yuena; Qi, Yafang; Han, Litao; Wu, Sixin
• Is Part Of: Small. Volume 18:Issue 39(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-26
• Subjects: crystallinity -- Cu(In, Ga)Se 2 -- Cu‐rich CIGS layer -- defects passivation -- solar cells -- solution process method; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202203443
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Solution processing of Cu(In, Ga)Se2 (CIGS) absorber is a highly promising strategy for a cost‐effective CIGS photovoltaic device. However, the device performance of solution‐processed CIGS solar cells is still hindered by the severe non‐radiative recombination resulting from deep defects and poor crystal quality. Here, a simple and effective precursor film engineering strategy is reported, where Cu‐rich (CGI >1) CIGS layer is incorporated into the bottom of the CIGS precursor film. It has been discovered that the incorporation of the Cu‐rich CIGS layer greatly improves the absorber crystallinity and reduces the trap state density. Accordingly, more efficient charge generation and charge transfer are realized. As a result of systematic processing optimization, the champion solution‐processed CIGS device delivers an improved open‐circuit voltage of 656 mV, current density of 33.15 mA cm −2, and fill factor of 73.78%, leading to the high efficiency of 16.05%. Abstract : Cu(In, Ga)Se2 (CIGS) precursor film engineering is performed in a solution‐processed CIGS absorber. Through the introduction of a Cu‐rich bottom layer, the CIGS absorber crystallization is improved and the detrimental deep level defects are reduced, resulting in increased depletion region width, better carrier collection ability, and suppressed carrier recombination. A solution‐processed CIGS solar cell with submicron‐thick absorber achieves a high efficiency of 16.05%.