Publication

Surface Restructuring of Hybrid Perovskite Crystals

​Surface Restructuring of Hybrid Perovskite Crystals
Banavoth Murali, Sukumar Dey, Ahmed L. Abdelhady, Wei Peng, Erkki Alarousu, Ahmad R. Kirmani, Namchul Cho, Smritakshi Phukan Sarmah, Manas R. Parida, Makhsud I. Saidaminov, Ayan A. Zhumekenov, Jingya Sun, Mohd S. Alias, Emre Yengel, Boon S. Ooi, Aram Amassian, Osman M. Bakr, and Omar F. Mohammed
ACS Energy Lett., 2016, 1, pp 1119–1126
Banavoth Murali, Sukumar Dey, Ahmed L. Abdelhady, Wei Peng, Erkki Alarousu, Ahmad R. Kirmani, Namchul Cho, Smritakshi Phukan Sarmah, Manas R. Parida, Makhsud I. Saidaminov, Ayan A. Zhumekenov, Jingya Sun, Mohd S. Alias, Emre Yengel, Boon S. Ooi, Aram Amas
hybrid perovskite crystals, semiconductor, optoelectronic
2016

 
Hybrid perovskite crystals have emerged as an important class of semiconductors because of their remarkable performance in optoelectronics devices. The interface structure and chemistry of these crystals are key determinants of the device’s performance. Unfortunately, little is known about the intrinsic properties of the surfaces of perovskite materials because extrinsic effects, such as complex microstructures, processing conditions, and hydration under ambient conditions, are thought to cause resistive losses and high leakage current in solar cells. We reveal the intrinsic structural and optoelectronic properties of both pristinely cleaved and aged surfaces of single crystals. We identify surface restructuring on the aged surfaces (visualized on the atomic-scale by scanning tunneling microscopy) that lead to compositional and optical bandgap changes as well as degradation of carrier dynamics, photocurrent, and solar cell device performance. The insights reported herein clarify the key variables involved in the performance of perovskite-based solar cells and fabrication of high-quality surface single crystals, thus paving the way toward their future exploitation in highly efficient solar cells.

DOI: 10.1021/acsenergylett.6b00517