nBn Based InAs/GaSb Type II Superlattice Detectors with an N-type Barrier Doping for the Long Wave Infrared Detection

Long-wave infrared detectors using the type-II InAs/GaSb strained superlattice (T2SL) material system with the nBn structure were designed and fabricated. The band gap energy of the T2SL material was calculated as a function of the thickness of the InAs and GaSb layers by the Kronig-Penney model. Growth of the barrier material () incorporated Te doping to reduce the dark current. The full width at half maximum (FWHM) of the satellite superlattice peak from the X-ray diffraction was around 45 arcsec. The cutoff wavelength of the fabricated device was (0.12 eV) at 80 K while under an applied bias of -1.4 V. The measured activation energy of the device was ~0.128 eV. The dark current density was shown to be at 80 K and with a bias -1.5 V. The responsivity was 0.58 A/W at at 80 K and with a bias of -1.5 V.