Improvement of tunnel compensated quantum well infrared detector

Abstract

Abstract To reduce the difficulty of the epitaxy caused by multiple quantum well infrared photodetector (QWIP) with tunnel compensation structure, an improved structure is proposed. In the new structure, the superlattices are located between the tunnel junction and the barrier as the infrared absorption region, eliminating the effect of doping concentration on the well width in the original structure. Theoretical analysis and experimental verification of the new structure are carried out. The experimental sample is a two-cycle device, each cycle contains a tunnel junction, a superlattice infrared absorption region and a thick barrier. The photosurface of the detector is 200 × 200 μm2 and the light is optically coupled by 45° oblique incidence. The results show that the optimal operating voltage of the sample is –1.1 V, the dark current is 2.99 × 10–8 A, and the blackbody detectivity is 1.352 × 108 cm·Hz1/2·W–1 at 77 K. Our experiments show that the new structure can work normally.