A Three-Step Method for the Deposition of Large Cuboids of Organic-Inorganic Perovskite and Application in Solar Cells

• Published in: Chemphyschem 2016-08, Vol.17 (15), p.2389-2394
• Main Authors: Shahbazi, Saeed, Malekshahi Byranvand, Mahdi, Tajabadi, Fariba, Afshar, Shahrara, Taghavinia, Nima
• Format: Article
• Language: English
• Subjects: electrochemistry; perovskite phases; solar cells; synthesis design; thin films
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201600229

A three‐step method for the deposition of CH3NH3PbI3 perovskite films with a high crystalline structure and large cuboid overlayer morphology is reported. The method includes PbI2 deposition, which is followed by dipping into a solution of C4H9NH3I (BAI) and (BA)2PbI4 perovskite formation. In the final step, the poorly thermodynamically stable (BA)2PbI4 phase converts into the more stable CH3NH3PbI3 perovskite by dipping into a solution of CH3NH3I. The final product is characterized by XRD, SEM, UV/Vis, and photoluminescence analysis methods. The experimental results indicate that the prepared perovskite has cuboids with high crystallinity and large sizes (up to 1 μm), as confirmed by XRD and SEM data. Photovoltaic investigations show that the three‐step method results in higher solar cell efficiency (15 % enhancement in efficiency) with a better reproducibility than the conventional two‐step deposition method. Slowly does it! A new three‐step method includes PbI2 deposition, followed by dipping into a solution of C4H9NH3I (BAI), to form (BA)2PbI4 perovskite. In the final step, the poorly thermodynamically stable (BA)2PbI4 perovskite converts into the more stable CH3NH3PbI3 phase through dipping into a solution of CH3NH3I (MAI; see figure). The product CH3NH3PbI3 perovskite films show highly crystalline structure with overlayers composed of large cuboids.