Effect of GaAsGaSb Combination StrainReducing Layer on SelfAssembled InAs Quantum Dots.pdfVIP

CHIN.PHYS.LETT. Vol.25, No.7(2008) 2649 Effect of GaAs/GaSb Combination Strain-Reducing Layer on Self-Assembled InAs Quantum Dots ∗ JIANG Zhong-Wei(ö ¥• ), WANG Wen-Xin(©#)∗∗ , GAO Han-Chao(pLJ ), LI Hui(oŸ ), YANG Cheng-Liang( ¤ û), HE Tao(Û 7), WU Dian-Zhong(ÇE® ), CHEN Hong(ø), ZHOU Jun-Ming(±þµ ) Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (Received 20 May 2008) Self-assembled quantum dots capping with a GaAs/Gasb combined strain-reduced layer (CSRL) are grown by MBE. Their structural and optical properties are investigated by AFM and photoluminescence (PL). PL mea- surements have shown that stronger emission about 1.3 µm can be obtained by Sb irradiation and capping QDs with 3 ML GaAs/2 ML GaSb CSRL at room temperature. The full width at half maximum (FWHM) of the PL spectrum is about 20.2 meV (19.9 meV) at room temperature (20 K), indicating that the QDs have high uniform, The result of FWHM is much better than the recently reported result, which is due to the fact that lower QD growth rate and growth interruption after the QDs deposition are adopted in our experiments. PACS: 78.67.Hc, 81.07.Ta, 78.55.Cr, 81.15.Hi So far, great progress has been achieved on limited regime.[12,13] It has been reported that the Sb the fabrication of optoelectronic devices based on irradiation on QDs or cover layers successfully im- self-assembled semiconductor nanostructures, espe- proved