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Title: Controllable Growth of Perovskite Films by Room-Temperature Air Exposure for Efficient Planar Heterojunction Photovoltaic Cells

A two-step-solution-processing approach has been established to grow void-free perovskite films for low-cost and high-performance planar heterojunction photovoltaic devices. We generally applied a high-temperature thermal annealing treatment in order to drive the diffusion of CH 3NH 3I precursor molecules into the compact PbI 2 layer to form perovskite films. But, thermal annealing for extended periods would lead to degraded device performance due to the defects generated by decomposition of perovskite into PbI 2. In this work, we explored a controllable layer-by-layer spin-coating method to grow bilayer CH 3NH 3I/PbI 2 films, and then drive the interdiffusion between PbI 2 and CH 3NH 3I layers by a simple room-temperature-air-exposure for making well-oriented, highly-crystalline perovskite films without thermal annealing. This high degree of crystallinity resulted in a carrier diffusion length of ~ 800 nm and high device efficiency of 15.6%, which is comparable to the reported values from thermally-annealed perovskite films based counterparts. Finally, the simplicity and high device performance of this processing approach is highly promising for direct integration into industrial-scale device manufacture.
 [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Univ. of Tennessee, Knoxville, TN (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Angewandte Chemie (International Edition)
Additional Journal Information:
Journal Name: Angewandte Chemie (International Edition); Journal Volume: 54; Journal Issue: 49; Journal ID: ISSN 1433-7851
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
14 SOLAR ENERGY; air exposure; in situ X-ray diffraction; perovskites; photovoltaic devices; thin films
OSTI Identifier: