Long Wavelength Type II InAs/GaSb Superlattice Photodetector Using Resonant Tunneling Diode Structure

摘要

We report on a long wavelength type-II InAs/GaSb superlattice photodetector using resonant tunneling diode (RTD) structure. The line width of the satellite peak of the x-ray diffraction curve of the as-grown sample is only 15.7 arcsec showing a very high structural quality. The response maximum wavelength of the RTD detector is 7.5 mu m and the 50% cutoff wavelength is 9.6 mu m at 77 K. The measured QE is 147% at 7.5 mu m when the applied bias voltage is 1.45 V and the corresponding responsivity is 8.9 A/W. This unusual QE is attributed to a large gain achieved when the device is under a resonant tunneling condition. The corresponding shot noise limited detectivity D* is 1.2 x 10(10)cm . root Hz/W at 1.45 V at 77 K.