Atomic force microscopy （AFM） and power-dependent micro-photoluminescence （μ-PL） spectroscopy are used to study the structure and exciton energy states in InAs quantum dots （QDs） grown on an In0.35Ga0.65As temp...Atomic force microscopy （AFM） and power-dependent micro-photoluminescence （μ-PL） spectroscopy are used to study the structure and exciton energy states in InAs quantum dots （QDs） grown on an In0.35Ga0.65As template on GaAs （311）B. The In0.35Ga0.65As template, consisting of a two-dimensionally modulated layer of closely packed connected cells, has a remarkable effect on the optical properties of the IhAs QDs. By comparing the emission spectra of the samples without and with InAs QDs and the work carried out by Gong et al. [J. Cryst. Growth 251 （2003） 150; Appl. Phys. Lett. 81 （2002） 3254] we conclude that the existence of the In0.35Ga0.65As template enhances the photo-absorption and therefore the exeiton emission from the QDs due to efficient exciton transfer from the template into the QDs. Furthermore, the PL emission from the QDs dearly reveals four discrete energy levels, S, P, D, and F with increasing excitation power.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10374018, 10321003, and 90401015, the Scientific Committee of Shanghai under Grant No 03DJ14001, and the Special Funds for Major State Basic Research Project of China under Grant No 2004CB619004.
文摘Atomic force microscopy （AFM） and power-dependent micro-photoluminescence （μ-PL） spectroscopy are used to study the structure and exciton energy states in InAs quantum dots （QDs） grown on an In0.35Ga0.65As template on GaAs （311）B. The In0.35Ga0.65As template, consisting of a two-dimensionally modulated layer of closely packed connected cells, has a remarkable effect on the optical properties of the IhAs QDs. By comparing the emission spectra of the samples without and with InAs QDs and the work carried out by Gong et al. [J. Cryst. Growth 251 （2003） 150; Appl. Phys. Lett. 81 （2002） 3254] we conclude that the existence of the In0.35Ga0.65As template enhances the photo-absorption and therefore the exeiton emission from the QDs due to efficient exciton transfer from the template into the QDs. Furthermore, the PL emission from the QDs dearly reveals four discrete energy levels, S, P, D, and F with increasing excitation power.
