High-quality inorganic–organic perovskite CH3NH3PbI3 single crystals for photo-detector applications

• Published in: Journal of materials science Vol. 52; no. 1; pp. 276 - 284
• Main Authors: Ding, Jianxu, Du, Songjie, Zhao, Ying, Zhang, Xiaojun, Zuo, Zhiyuan, Cui, Hongzhi, Zhan, Xiaoyuan, Gu, Yijie, Sun, Haiqing
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-01-2017; Springer Nature B.V
• Subjects: Absorptivity; Butyrolactone; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystal growth; Crystallography and Scattering Methods; Gold; Materials Science; Original Paper; Perovskites; Photometers; Polymer Sciences; Quantum efficiency; Screw dislocations; Sensors; Shape optimization; Single crystals; Solid Mechanics; Unit cell; Seed Crystal; Growth Step; High Responsivity; PbI2; External Quantum Efficiency
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-016-0329-2

Single crystals of organolead trihalide perovskites (CH
3
NH
3
PbI
3
) are supposed to be one of the most promising materials as photo-detectors. Because of their large absorption coefficient, long-range balanced electron, and hole-transport lengths, it is considered to break through the responsivity and efficiency. To systematically investigate the potentiality as photo-detector, high-quality CH
3
NH
3
PbI
3
single crystals with large size are highly demanded. In the paper, large CH
3
NH
3
PbI
3
single crystals with various crystal shapes were grown from γ-butyrolactone. At optimized precursor concentration and growth temperature, the growth rate was fixed at about 0.2 mm h
−1
. Under such growth conditions, the growth steps, originated from screw dislocation on (100) facet, were revealed to be about 0.45 nm. This value is corresponded to half of the unit cell, implying the slow growth rate of (100) facet. With slow growth rate, the absorption edge of the CH
3
NH
3
PbI
3
single crystal was extended to 860 nm, correlated with a calculated bandgap of ~1.44 eV. By depositing a pair of Au electrodes, a metal–semiconductor–metal (MSM) photo-detector on the basis of the CH
3
NH
3
PbI
3
single crystal active layer (3 mm) was fabricated and its photo-response features were investigated systematically. About 2.531 A W
−1
responsivity was obtained from the device under 780 nm laser illumination, while the external quantum efficiency reached to 396.20 %, better than some GaN, GaAs, and GaP photo-detectors with a MSM device structure.