Observation of bandgap narrowing in <i>p</i> -type doped GeSn alloys
Abstract
A series of p-type doped GeSn samples has been epitaxially grown by the ultra-high vacuum chemical vapor deposition method, and direct bandgap narrowing (BGN) is observed through photoluminescence and infrared spectroscopic ellipsometry measurements, demonstrating a positive correspondence with increasing carrier concentration. The experimental results could be fitted by a square-root correlation of ΔE0 (meV) = −13.69 N/1018 cm−3. The theoretical expression for the BGN of p-type Ge and GeSn has been revisited with updated carrier effective masses, and satisfactory agreement with the experimental data has been achieved. The results show that BGN in p-GeSn is more pronounced as compared to those in n-type counterparts, suggesting that special attention should be paid in future scientific research and device designing processes that involve such materials.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (11)
Caile Wang
State Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,
Yue Li
Junyu Chang
State Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,
Zhengjie Wu
State Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,
Ziyu Liu
Department of Physics
Ruoyun Ji
State Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,
Dong Han
National Synchrotron Radiation Laboratory
Chao Zhao
Shanghai Institute of Measurement and Testing Technology, 1500 Zhang-Heng Road, Shanghai 201203, P.R. China
Hui Cong
State Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,
Chi Xu
Department of Dental Implant Center, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, No. 9 Fanjiacun Road, Fengtai District, Beijing 100070, China
Chunlai Xue
State Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences 1 , Beijing 100083,