Crystallography-derived optoelectronic and photovoltaic properties of CsPbBr3 perovskite single crystals as revealed by in situ transmission electron microscopy. (September 2020)

• Record Type: Journal Article
• Authors: Zhang, Chao; Fernando, Joseph F.S.; Firestein, Konstantin L.; von Treifeldt, Joel E.; Siriwardena, Dumindu P.; Fang, Xiaosheng; Golberg, Dmitri V.
• Is Part Of: Applied materials today. Volume 20(2020)
• Publication Date: 2020-09
• Subjects: In situ TEM -- Inorganic perovskite -- Single crystal -- Optoelectronics -- Photovoltaics; : TEM Transmission Electron Microscopy -- SAED Selected Area Electron Diffraction -- ON/OFF ratio light-on light-off ratio -- NA Numerical Aperture -- Cs-STEM Spherical aberration-corrected Scanning Transmission Electron Microscopy; Materials science -- Periodicals; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1016/j.apmt.2020.100788
• Languages: English
• ISSNs: 2352-9407

Abstract

Highlights: Free-standing CsPbBr3 perovskite crystals are grown and probed by in situ TEM. Photocurrents and photovoltages on different crystal planes are selectively measured. Photocurrent spectroscopy reveals pressure-induced blue shift of cut-off wavelength. Pristine and pressed (101) facets deliver higher photovoltage. Abstract: Given the high importance of CsPbBr3 perovskite crystals for optoelectronic and photovoltaic device applications, surprisingly, relatively little work has been done to assess the impact of crystalline orientations and/or surface contacts on their performance. Herein, photocurrent and photovoltage properties of CsPbBr3 single crystals are selectively measured on (001) and (101) facets in pristine and compressed conditions using light-and-stress-compatible in situ high-resolution transmission electron microscopy (TEM). The photocurrent-to-dark-current ratios on (001) and (101) facets are found to be comparable, showing a minimal statistical discrepancy. The TEM-derived photocurrent spectroscopies revealed slight blue shifts of the cut-off wavelengths under crystal pressing. By contrast, the photovoltage values measured on the two regarded facets significantly differ, and this difference is sustained under in situ compression in the TEM. The higher values apparent for (101) facets provide valuable information for a smart device design and perovskite crystal applications in photoelectronic and photovoltaic fields. Graphical abstract: Image, graphical abstract