AVS 65th International Symposium & Exhibition
    Electronic Materials and Photonics Division Tuesday Sessions
       Session EM+2D+AN+MI+MP+NS-TuA

Paper EM+2D+AN+MI+MP+NS-TuA4
Modification of Bandgap for Lead-Free Double Perovskite Cs2AgInCl6 with Bi Doping

Tuesday, October 23, 2018, 3:20 pm, Room 101A

Session: Solar/Energy Harvesting and Quantum Materials and Applications
Presenter: Hassan Siddique, University of Science and Technology of China
Authors: H. Siddique, University of Science and Technology of China
H. Da, University of Science and Technology of China
X.Q. Wang, University of Science and Technology of China
R.C. Dai, University of Science and Technology of China
Z.P. Wang, University of Science and Technology of China
Z.J. Ding, University of Science and Technology of China
Z.M. Zhang, University of Science and Technology of China
Correspondent: Click to Email
Lead halide perovskites have the excellent luminescent properties but exist some vital disadvantages such as instability and Pb toxicity. Lead-free double perovskites draw attention due to a possible candidate for environment-friendly materials. Direct bandgap lead-free halide of Cs2AgInCl6 is one of them. [1] In this work Bi doping Cs2AgInCl6 (CAIC) was successfully prepared. Bi dopant above 15% CAIC can restrict the parity forbidden transition responding to sub absorption peak around 600 nm.[2] On the other hand, the intensity of photoluminescence enhances with the increasing Bi dopant and touches the maximum around 30% doping, then gradually loses its intensity with further doping due to the mechanism of the concentration quenching at room temperature. Bi doping in CAIC can also modify the band gap. The absorption spectra indicate that the band gap reduces from 3.10eV without Bi doping to 2.68eV for Cs2AgIn0.30 Bi0.70Cl6. PL decay life time reveals the good intrinsic excitonic feature with less defect trappers [3]. Average life time for Cs2AgIn0.70 Bi0.30Cl6 is 490 ns which is least among all other Cs2AgIn(1-x)BixCl6 doping. Thermogravimetric analysis (TGA) result reveals thermal stability of Cs2AgIn0.30 Bi0.70Cl6 for the high-temperature 506oC. The Bi doping can decrease the band gap, restrict defect states, enhance PL and improve stability; these good performances make Cs2AgIn(1-x)BixCl6 more suitable for optoelectronic properties.