Tunable bandgap in hybrid perovskite CH{sub 3}NH{sub 3}Pb(Br{sub 3−y}X{sub y}) single crystals and photodetector applications

• Published in: AIP advances Vol. 6; no. 4
• Main Authors: Wang, L., Duan, R. F., Huang, F., Wei, T. B., Liu, Z. Q., Wang, J. X., Li, J. M., Yuan, G. D., State Key Lab of Silicon Materials, Zhejiang University, Hangzhou 310027
• Format: Journal Article
• Language: English
• Published: United States 15.04.2016
• Subjects: BROMINE COMPOUNDS; CHLORINE; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; HEATING RATE; IODINE; LEAD COMPOUNDS; MASS; MONOCRYSTALS; NUCLEATION; OPTICAL PROPERTIES; PEROVSKITE; PHOTODETECTORS; SYNTHESIS; TEMPERATURE CONTROL; WAVELENGTHS
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.4948312

We report the synthesis of CH{sub 3}NH{sub 3}Pb(Br{sub 3−y}X{sub y}) (X=Cl and I) single crystals via a stepwise temperature control approach. High-quality CH{sub 3}NH{sub 3}Pb(Br{sub 3−y}X{sub y}) crystals with a tunable bandgap from 1.92 eV to 2.53 eV have been prepared successfully in this way. And further experiments revealed the influence of halogen content and preparation temperature on the structural and optical properties of these crystals. It is observed that chlorine can lower the critical nucleation energy, which results in crystallizing at lower temperature with the chlorine content increasing, while the nucleation energy increases slowly with increasing iodine content. Moreover, in contrast to Frank–van der Merwe growth with low heating rate, high heating rate leads to a mass of small size single crystals and Stranski-Krastanov growth. The single crystals with tunable band gap and impressive characteristics enable us to fabricate high performance photodetectors for different wavelengths.