Energy state of InGaAs quantum dots on SiO2-patterned vicinal substrate
1 Photonic Energy Research Center, Korea Photonics Technology Institute, Wolchul dong 971-35, Buk-gu, Gwangju, Korea
2 Research Center for Integrated Quantum Electronics, Hokkaido University, North 13 West 8, Sapporo 060-8628, Japan
Nanoscale Research Letters 2012, 7:104 doi:10.1186/1556-276X-7-104Published: 6 February 2012
The optical properties of In0.8Ga0.2As self-assembled quantum dots (SAQDs) grown on GaAs wire structures formed by utilizing SiO2-patterned exact and 5°-off (001) GaAs substrates have been studied with micro-photoluminescence (μ-PL). Single PL peak was occurred for In0.8Ga0.2As SAQDs grown on SiO2-patterned exact (001) GaAs, whereas double PL peaks were showed for SAQDs grown on 5°-off (001) GaAs substrates as the width of the opening windows increased. The power-dependent μ-PL spectra show that the first and second peaks of these double peaks were originated from the well-defined ground and excited state, respectively. These results demonstrated that In0.8Ga0.2As SAQDs selectively grown by utilizing SiO2-patterned 5°-off (001) GaAs substrates have well-defined zero-dimensional quantum states.