Effects of passivation and extraction surface trap density on the 1/f noise of HgCdTe photoconductive detector
- National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Electrical Engineering
- Chung Shan Inst. of Science and Technology, Lung-Tan (Taiwan, Province of China)
Experimental results are presented for noise voltage, responsivity, and specific detectivity (D*) for the long wavelength infrared (IR) HgCdTe photoconductive detectors. Hg{sub 0.8}Cd{sub 0.2}Te photoconductive detectors passivated with ZnS/photo-enhanced native oxide have an improved noise spectral density and D* than the detectors passivated with only ZnS. The low frequency 1/f noise charges were measured for a Hg{sub 0.8}Dc{sub 0.2}Te photo detector, as a function of bias at 77 K, and the effective surface trap density determined from the 1/f noise charges measured at 1 Hz. It was found that the surface effective trap densities of stacked passivated sample and the sample passivated only with ZnS are close to 4 {times} 10{sup 17} and 9 {times} 10{sup 17} cm{sup {minus}2}{center_dot}eV{sup {minus}1} under 0.4 V bias and 1 {mu}s integration time, respectively. The authors found that the numerical values of noise are strongly dependent upon surface passivation properties. It can be seen clearly that an HgCdTe photo detector with a stacked ZnS/photo-enhanced native oxide passivation is better than the HgCdTe photo detector passivated with a single ZnS layer.
- OSTI ID:
- 449545
- Journal Information:
- IEEE Photonics Technology Letters, Journal Name: IEEE Photonics Technology Letters Journal Issue: 2 Vol. 9; ISSN 1041-1135; ISSN IPTLEL
- Country of Publication:
- United States
- Language:
- English
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