Open AccessA new phenomenon of photoconductive InSb detector under the irradiation of out-band laser
Author(s) -
Xin Zheng,
Tian Jiang,
Xin Cheng,
Houman Jiang,
Qin Lu
Publication year - 2012
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.61.047302
Subject(s) - photoconductivity , materials science , laser , detector , optoelectronics , irradiation , electron mobility , photon energy , band gap , absorption (acoustics) , photon , optics , physics , nuclear physics , composite material
A new phenomenon is observed when a photoconductive InSb detector with 0.228eV band gap is irradiated by 10.6 μm laser, whose photon energy is 0.12 eV. The detector is heated by this out-band laser, due to the absorption of laser energy. However, a transformation temperature T0 exists in this process. When the temperature of the detector, T, is lower than T0, the number of carriers remains constant but the conductivity changes because of a change in mobility. The mobility decreases with the increase of temperature and varies as T-2.35. At T>T0, the concentration of thermally-activated carrier increases with temperature, which is proportional to exp (-Eg/2k0T). As a result, the influence of carrier concentration becomes more and more important. As a result, the output of the detector decreases. In a word, the output voltage of photoconductive detector results from the temperature dependence of mobility and concentration of carriers. This work provides an experimental basis for improving the carrier transport model.