The structural and optical properties of GaSb/InGaAs type-II quantum dots grown on InP (100) substrate
1 School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China
2 National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
3 Engineering Research Center of Solid-State Lighting, School of Electrical Engineering and Automation, Tianjin Polytechnic University, Tianjin, 300160, China
Nanoscale Research Letters 2012, 7:87 doi:10.1186/1556-276X-7-87Published: 25 January 2012
We have investigated the structural and optical properties of type-II GaSb/InGaAs quantum dots [QDs] grown on InP (100) substrate by molecular beam epitaxy. Rectangular-shaped GaSb QDs were well developed and no nanodash-like structures which could be easily found in the InAs/InP QD system were formed. Low-temperature photoluminescence spectra show there are two peaks centered at 0.75eV and 0.76ev. The low-energy peak blueshifted with increasing excitation power is identified as the indirect transition from the InGaAs conduction band to the GaSb hole level (type-II), and the high-energy peak is identified as the direct transition (type-I) of GaSb QDs. This material system shows a promising application on quantum-dot infrared detectors and quantum-dot field-effect transistor.