Density-dependent carrier dynamics in a quantum dots-in-a-well heterostructure
Abstract
The incorporation of semiconductor quantum dots into different heterostructures for applications in nanoscale lasing and amplification has been an active area of research in recent years. Here, we use ultrafast differential transmission spectroscopy to temporally and spectrally resolve density-dependent carrier dynamics in a quantum dots-in-a-well (DWELL) heterostructure. We observe excitation-dependent shifts of the quantum dot energy levels at low densities, while at high densities we observe an anomalous induced absorption at the quantum dot excited state that is correlated with quantum well population dynamics. These studies reveal unique Coulomb interaction-induced phenomena with important implications for DWELL-based lasers and amplifiers.
- Publication:
-
Applied Physics Letters
- Pub Date:
- January 2010
- DOI:
- 10.1063/1.3294309
- Bibcode:
- 2010ApPhL..96c1110P
- Keywords:
-
- carrier density;
- excited states;
- gallium arsenide;
- high-speed optical techniques;
- III-V semiconductors;
- indium compounds;
- photoluminescence;
- semiconductor heterojunctions;
- semiconductor quantum dots;
- semiconductor quantum wells;
- 73.63.Kv;
- 73.40.Kp;
- 72.20.Jv;
- 78.67.Hc;
- 78.55.Cr;
- 78.47.J-;
- Quantum dots;
- III-V semiconductor-to-semiconductor contacts p-n junctions and heterojunctions;
- Charge carriers: generation recombination lifetime and trapping;
- Quantum dots;
- III-V semiconductors;
- Ultrafast pump/probe spectroscopy