Atomic force microscopy investigation of a step generation and bunching on the (100) facet of a CH3NH3PbI3 crystal, grown from γ‐Butyrolactone. Issue 4 (3rd April 2017)

• Record Type: Journal Article
• Authors: Ding, Jianxu; Zhao, Ying; Sun, Yingshuang; Du, Songjie; Cui, Hongzhi; Jing, Lin; Cheng, Xiaohua; Zuo, Zhiyuan; Zhan, Xiaoyuan
• Is Part Of: Crystal research and technology. Volume 52:Issue 4(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-04-03
• Subjects: CH3NH3PbI3 -- Single crystal growth -- Surface structures -- AFM -- Step bunching; Crystallography -- Periodicals; 548
• DOI: 10.1002/crat.201700021
• Languages: English
• ISSNs: 0232-1300

Abstract

Abstract : The steps on the (100) facet of CH3 NH3 PbI3 were observed to origanate from a screw dislocation, whose height's equal to half of the unit cell. These steps could form bunched steps with even numbers of elementary steps. In terms of the surface structures and solution stabilities, large size and high quality CH3 NH3 PbI3 single crystals were grown. Abstract : Single crystal of organolead trihalide perovskite (CH3 NH3 PbI3 ) is proved to be one of the most promising semiconductor materials. Growing large size and high quality CH3 NH3 PbI3 single crystals is urgently demanded by photoelectric device applications. However, the growth mechanism in microscopic scale for CH3 NH3 PbI3 single crystal is still unrevealed. In this paper, we are focusing on observing surface structures on (100) facet of CH3 NH3 PbI3 single crystal via atomic force microscopy (AFM), especially surface structure conversion related to growth kinetics. The results reveal that the growth of (100) facet of CH3 NH3 PbI3 single crystal is dependent on bunching steps and step slope. The elemental steps, with step height about 0.45 nm, corresponded to half of the unit cell, are generated from screw dislocations when the growth rate is about 0.2 mm per hour. Elemental steps can bunch together and form bunching steps with growth rate of 0.5 mm per hour, in which only even numbers elementary steps are involved, suggesting even numbers elementary steps are stable than that of odd numbers. Additionally, in terms of the surface structures and solution stabilities, large size and high quality CH3 NH3 PbI3 single crystals were grown.