HIGH-PERFORMANCE UNCOOLED INASSBP INGAAS PHOTODIODES FOR THE 1.8-3.4-MU-M WAVELENGTH RANGE/

Room temperature In,,,,Ga,,As photodiodes with an InAS(0.36)Sb(0.20)P( 0.14) transparent window layer operating in the mid-infrared region ov er the wavelength range 1.8-3.4 mu m are reported. The InAs0.36Sb0.20P 0.44/In0.97Ga0.03 As heterojunction photodiodes were grown on p-type ( 100) InAs substrates by liquid phase epitaxy (LPE). Basic detector cha racteristics have been measured and compared with other detectors in t his wavelength range. The typical detectivity of the photodiodes is 1. 2 x 10(10) cm Hz(1/2)/W at room temperature, which compares very favou rably with that of TE cooled HgCdTe and is at least three times that o f cooled PbSe photoconductors. The InAs0.36Sb0.20P0.44/In0.97Ga0.03 As hererojunction photodiodes offer the advantage of increased sensitivi ty and extended wavelength response at room temperature compared with that of currently available commercial photodetectors, making them an attractive alternative for a number of mid-infrared applications inclu ding optical gas sensors and infrared spectrometers. (C) 1997 Elsevier Science B.V.