The state filling effect in p-doped InGaAs/GaAs quantum dots

• Published in: Journal of physics. Condensed matter Vol. 19; no. 38; pp. 386213 - 386213 (10)
• Main Authors: Wen, X M, Dao, L V, Hannaford, P, Mokkapati, S, Tan, H H, Jagadish, C
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 26.09.2007; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Nanocrystals and nanoparticles; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Confinement; Gallium arsenides; Excitation intensity; Quantum dots; Photoluminescence; Frequency conversion; Self-assembled layers; Modulation doping; Phosphorus additions; Energy level population; Time resolved spectra; Indium arsenides; Energy-level transitions; Rate equation
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/19/38/386213

The electron dynamics in modulation p-doped InGaAs/GaAs self-assembled quantum dots have been studied by time-integrated and time-resolved up-conversion photoluminescence. A significant state filling effect is observed with exclusion of the phonon bottleneck effect. The rise time and decay time are found to vary with the excitation intensity for the ground state and excited states of the quantum dots. In the low intensity regime the rise time decreases with increasing excitation intensity because of the increased scattering between the photoexcited electrons and excess holes. By contrast, in the high excitation regime the rise time exhibits a slight decrease due to the state filling effect. A simplified rate equation model indicates that the modulation p-doped quantum dots exhibit an increasing saturation factor with increasing detection photon energy based on the theory of parabolic confinement of the quantum dots, which is consistent with the observed excitation dependence.