Tunnel Compensated Multiple Quantum Well Infrared Detector

Infrared detectors are devices that convert infrared radiation energy into physical quantity that can be easily measured.They are widely used in military,meteorological,agricultural,industrial,medical and other fields.Semiconductor infrared photodetectors have many structures.Among them,quantum well detectors have the advantages of good uniformity and high reliability,which means they are suitable for fabricating large-scale focal plane array.Meanwhile,they are easy to fabricate into two or more color detectors.However,the working principle of quantum well infrared detector determines that the performance of the detector is difficult to improve.Most researchers focus on improving the efficiency of optical coupling.In addition,some researchers have proposed ways to improve the internal structure of devices.Among them,there is an improved quantum well infrared detector based on tunnel compensation.The photoelectric current of the detector can be increased by increasing the number of quantum wels.The defect is that the low level of doping control in epitaxy is easy to cause device failure.Based on this,an improved structure is proposed by inserting multi-quantum wels between tunnel junctions and barriers.The multi-quantum wels replaced single quantum well and become the infrared absorption region of the detector.The new structure eliminates the effect of doping concentration on quantum well width and reduces the difficulty of epitaxy growth.Tunnel compensated multi-quantum well infrared detector is composed of multi-period series basic units,which are divide into a tunnel junction,multi-quantum wells and a barrier.This article mainly has the following contents:1.The application scope and types of infrared detectors are introduced.The development of quantum well detectors and tunnel compensated quantum well infrared detectors are introduced.The main contents of this paper are listed.2.The working principle of the tunnel compensated multi-quantum well infrared detector is introduced.The parameters of the key structure of the detector are calculated.:3.The transport and noise characteristics of electrons in devices is introduced.4.The structure and fabrication process of tunnel compensated multi-quantum well infrared detector are introduced.Volt-ampere characteristics,blackbody response and spectral response of double-period tunnel compensated multi-quantum well infrared detectors were tested.The photosurface of the detector is 200?m×200?m and the light is optically coupled by 45°oblique incidence.The results show that the optimal operating voltage of the sample is-1.1V,the dark current is 0.221?A,peak absorption wavelength is about 7.7?m,and the blackbody detectivity is 1.267×10⁸cm·Hz^1/2/W at77 K.