Pressure effects on nanoprobe photoluminescence of quasi-zero-dimensional confinement quantum dots

✍ Scribed by Kazunari Ozasa; Sintaro Nomura; Yoshinobu Aoyagi

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 842 KB
• Volume: 30
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.2001.1002

✦ Synopsis

Nanoprobe near-field photoluminescence (PL) of InGaAs(P) dots with quasi-zero-dimensional (quasi-0D) confinement with various degrees of 0D/2D has been investigated by studying probe-induced pressure effects and probe-bias effects. Fine PL peaks of 0D confinement are superimposed on quantum well (QW) peaks for quasi-0D structures, which proves the coexistence of 0D and two-dimensional (2D) confinement in the same layer. Large blue shifts of approximately 100 meV were observed to occur with pressure increase for 0D fine PL peaks, but no shift was observed for the QW peak. The fine 0D peaks were eliminated by larger probe-induced pressures, which should be attributed to carrier diffusion rather than to -X crossover in energy levels. The QW peak increased with the positive probe bias, while 0D fine PL peaks showed a smaller increase with red shifts up to 8-9 meV. The results obtained can be explained by the excitation of immobile excitons in 0D potentials to mobile carriers in the 2D (QW) layer.