Controlling nucleation and growth of metal halide perovskite thin films for high-Efficiency perovskite solar cells

Journal article

Metal halide perovskite thin films can be crystallized via a broad range of solution-based routes. However, the quality of the final films is strongly dependent upon small changes in solution composition and processing parameters. Here, this study demonstrates that a fractional substitution of PbCl2 with PbI2 in the 3CH3 NH3 I:PbCl2 mixed-halide starting solution has a profound influence upon the ensuing thin-film crystallization. The presence of PbI2 in the precursor induces a uniform distribution of regular quadrilateral-shaped CH3 NH3 PbI3 perovskite crystals in as-cast films, which subsequently grow to form pinhole-free perovskite films with highly crystalline domains. With this new formulation of 3CH3 NH3 I:0.98PbCl2 :0.02PbI2 , this study achieves a 19.1% current-voltage measured power conversion efficiency and a 17.2% stabilized power output in regular planar heterojunction solar cells.

Authors: Sakai, N; Wang, Z; Burlakov, V; Lim, J; McMeekin, D

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Small
• Volume: 13
• Issue: 14
• Pages: 1-8
• Publication date: 2017-02-02
• Acceptance date: 2016-12-16
• DOI: 10.1002/smll.201602808
• EISSN: 1613-6829
• ISSN: 1613-6810
• Pmid: 28151573
• Language: English
• Keywords: thin-film crystallization; nucleation; perovskite photovoltaics; lead halide mix