Quantum dot infrared photodetectors
Abstract
Self-assembled strained semiconductor nanostructures have been grown on GaAs substrates to fabricate quantum dot infrared photodetectors. State-filling photoluminescence experiments have been used to probe the zero-dimensional states and revealed four atomic-like shells (s,p,d,f) with an excitonic intersublevel energy spacing which was adjusted to ∼60 meV. The lower electronic shells were populated with carriers by n doping the heterostructure, and transitions from the occupied quantum dot states to the wetting layer or to the continuum states resulted in infrared photodetection. We demonstrate broadband normal-incidence detection with a responsivity of a few hundred mA/W at a detection wavelength of ∼5 μm.
- Publication:
-
Applied Physics Letters
- Pub Date:
- January 2001
- DOI:
- 10.1063/1.1337649
- Bibcode:
- 2001ApPhL..78...79L
- Keywords:
-
- 73.21.La;
- 78.67.Hc;
- 07.57.Kp;
- 85.60.Gz;
- 78.55.Cr;
- 78.66.Fd;
- 81.07.Ta;
- 85.35.Be;
- 73.20.Mf;
- 71.35.-y;
- Quantum dots;
- Quantum dots;
- Bolometers;
- infrared submillimeter wave microwave and radiowave receivers and detectors;
- Photodetectors;
- III-V semiconductors;
- III-V semiconductors;
- Quantum dots;
- Quantum well devices;
- Collective excitations;
- Excitons and related phenomena