Phase Control of Organometal Halide Perovskites for Development of Highly Efficient Solar Cells

Tae Woong Kim; Satoshi Uchida; Myoung Kim; Sang Geun Cho; So Jeong Kim; Takashi Kondo; Hiroshi Segawa

doi:10.1021/acsami.2c22769

Phase Control of Organometal Halide Perovskites for Development of Highly Efficient Solar Cells

ACS Appl Mater Interfaces. 2023 May 10;15(18):21974-21981. doi: 10.1021/acsami.2c22769. Epub 2023 Mar 31.

Authors

Tae Woong Kim¹, Satoshi Uchida², Myoung Kim², Sang Geun Cho¹, So Jeong Kim¹, Takashi Kondo^{2

3}, Hiroshi Segawa^{2

4}

Affiliations

¹ Department of Applied Chemistry, College of Science and Technology, Konkuk University, Chungwon-daero 268, Chungju-si 27478, Chungcheongbuk-do, Korea.
² Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo 153-8904, Japan.
³ Department of Materials Engineering, Faculty of Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan.
⁴ Department of General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.

PMID: 37000640
DOI: 10.1021/acsami.2c22769

Abstract

To develop a highly efficient solar cell using organometal halide perovskites, its microscale structure control is one of the most important factors because the microstructural defects inside the organometal halide perovskite are harmful to charge carrier flow and, thus, degrade device performance. In this study, we confirmed the existence of large physical gaps at the grain boundary in a methylammonium iodide (MAPbI₃, MA = CH₃NH₃) perovskite with transmission electron microscopy (TEM) analysis and revealed that the physical gap prevents charge carrier flow in the MAPbI₃ perovskite. To minimize the physical gap and its negative influences, the grain size of the MAPbI₃ perovskite was optimized by increasing the portion of the cubic phase via microstructural phase control using liquid nitrogen (LN₂). Through microstructural phase control of the MAPbI₃ perovskite, its grain boundaries and physical gap were significantly decreased, and 20.23% power conversion efficiency (PCE) was achieved with a single cation MAPbI₃ perovskite solar cell.

Keywords: in situ analysis; interface perovskite; perovskite solar cell; phase control; transmission electron microscopy.