With the rapid development of organic-inorganic lead halide perovskite photovoltaics, increasingly more attentions are paid to explore the growth mechanism and precisely control the quality of perovskite films. In this study, we propose a “stitching effect” to fabricate high quality perovskite films by using chlorobenzene (CB) as an anti-solvent and isopropyl alcohol (IPA) as an additive into this anti-solvent. Because of the existence of IPA, CB can be efficiently released from the gaps of perovskite precursors and the perovskite film formation can be slightly modified in a controlled manner. More homogeneous surface morphology and larger grain size of perovskite films were achieved via this process. The reduced grain boundaries ensure low surface defect density and good carrier transport in the perovskite layer. Meanwhile, we also performed the Fourier transform infrared (FTIR) spectroscopy to investigate the film growth mechanism of unannealed and annealed perovskite films. Solar cells fabricated by using the “stitching effect” exhibited a best efficiency of 19.2%. Our results show that solvent and solvent additives dramatically influenced the formation and crystallization processes for perovskite materials due to their different coordination and extraction capabilities. This method presents a new path towards controlling the growth and morphology of perovskite films.
|Number of pages||10|
|State||Published - Sep 2017|
Bibliographical noteFunding Information:
This work was supported by the National Natural Science Foundation of China under grant nos. 61421002, 61574029, and 61371046. This work was also partially supported by University of Kentucky.
© 2017 Elsevier Ltd
- Mixed solvent
- Morphology engeering
- Perovskite solar cells
- Stitching effect
- Triple cation
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science (all)
- Electrical and Electronic Engineering