We demonstrate the first long-wavelength quantum-well infrared photodetectors using the lattice-matched n-doped InGaAlAs-InP materials system. Samples with AlAs mole fractions of 0.0, 0.1, and 0.15 result in cutoff wavelengths of 8.5, 13.3, and 19.4 μm, respectively. A 45° facet coupled illumination responsivity of R = 0.37 A/W and detectivity of Dλ* = 3 × 108 cm ·√Hz · W-1 at T = 77 K, for a cutoff wavelength λc = 13.3 μm have been achieved. Based on the measured intersubband photoresponse wavelength, a null conduction band offset is expected for In0.52Ga0.21Al0.27As-InP heterojunctions.
- Infrared detector
- Quantum-well device
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering