Carrier dynamics of Mn-induced states in GaN thin films

• Main Authors: Yu-Ting Chen, Chi-Yuan Yang, Po-Cheng Chen, Jinn-Kong Sheu, Kung-Hsuan Lin
• Format: Article
• Language: English
• Published: Nature Publishing Group 2017-07-01
• Series: Scientific Reports
• Online Access: https://doi.org/10.1038/s41598-017-06316-7

Abstract GaN-based materials are widely used for light emission devices, but the intrinsic property of wide bandgap makes it improper for photovoltaic applications. Recently, manganese was doped into GaN for absorption of visible light, and the conversion efficiency of GaN-based solar cells has been greatly improved. We conducted transient optical measurements to study the carrier dynamics of Mn-doped GaN. The lifetime of carriers in the Mn-related intermediate bands (at 1.5 eV above the valence band edge) is around 1.7 ns. The carrier relaxation within the Mn-induced bandtail states was on the order of a few hundred picoseconds. The relaxation times of different states are important parameters for optimization of conversion efficiency for intermediate-band solar cells.