Analysis of the effect of surface passivant charges on HgCdTe photoconductive detectors

Pal, R.; Bhan, R. K.; Chhabra, K.C.; Agnihotri, O.P.

doi:10.1088/0268-1242/11/2/015

Cited by 14 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Passivants can also modify performance. For example, passivants for MCT photoconductive detectors give rise to positive fixed charges, which alter performance of these photoconductive detectors . Density functional theory studies have also found that absorption of transition metals on single‐layer phosphorene could hinder use of this material for spintronics applications .…”

Section: Long‐term Stable and Reliable Devicesmentioning

confidence: 99%

Recent Progress on Stability and Passivation of Black Phosphorus

et al. 2018

View full text Add to dashboard Cite

From a fundamental science perspective, black phosphorus (BP) is a canonical example of a material that possesses fascinating surface and electronic properties. It has extraordinary in-plane anisotropic electrical, optical, and vibrational states, as well as a tunable band gap. However, instability of the surface due to chemical degradation in ambient conditions remains a major impediment to its prospective applications. Early studies were limited by the degradation of black phosphorous surfaces in air. Recently, several robust strategies have been developed to mitigate these issues, and these novel developments can potentially allow researchers to exploit the extraordinary properties of this material and devices made out of it. Here, the fundamental chemistry of BP degradation and the tremendous progress made to address this issue are extensively reviewed. Device performances of encapsulated BP are also compared with nonencapsulated BP. In addition, BP possesses sensitive anisotropic photophysical surface properties such as excitons, surface plasmons/phonons, and topologically protected and Dirac semi-metallic surface states. Ambient degradation as well as any passivation method used to protect the surface could affect the intrinsic surface properties of BP. These properties and the extent of their modifications by both the degradation and passivation are reviewed.

show abstract

Section: Long‐term Stable and Reliable Devicesmentioning

confidence: 99%

Recent Progress on Stability and Passivation of Black Phosphorus

et al. 2018

View full text Add to dashboard Cite

show abstract

“…For higher values of SRH trap density, the non-radiative SRH lifetime dictates the effective value of the carrier lifetime. However, when interfacial surface recombination velocity is high (10 2 -10 3 m/s) (Pal et al 1996) the effective lifetime is determined by the surface recombination rather than SRH recombination via traps. The dependence of the photoconductor gain on SRH trap density and surface recombination velocity at the interfaces is shown separately in Figs.…”

Section: Resultsmentioning

confidence: 99%

Modeling and analysis of photoconductive detectors based on Hg1-x Cd x Te for free space optical communication

2007

View full text Add to dashboard Cite

In this paper we report a theoretical analysis of a long wavelength photoconductive detector for characterizing and optimizing the device in respect of voltage responsivity, quantum efficiency, detectivity and noise equivalent power. The model has been applied to examine the potential of an n-type Hg 0.77 Cd 0.23 Te photoconductive detector for possible application in free space optical communication system operating at the atmospheric window near 9.6 µ m. In the present analysis we have taken into account all the major recombination mechanisms (e.g., Radiative, Auger, and Shockley-Read-Hall types) including the effect of surface recombination at the interfaces that shape the characteristics of photoconductor. The results obtained on the basis of our analysis reveal that in the absence of surface recombination the device exhibits a peak quantum efficiency of 90%, a maximum detectivity of 10 8 MHz 1/2 /W at 77 K, a 3 dB bandwidth of 117.86 MHz and noise voltage of 5.4 × 10 −6 V/Hz 1/2 . The sweep-out effect has been found to degrade the detectivity nearly by a factor of 10 at the same temperature and wavelength of operation. The estimated noise equivalent power of the photodetector is of the order of 10 −9 W at 9.6 µm wavelength.

show abstract

“…Detailed results on dependence of lifetime on surface conditions such as Q ss , n ss and SRV are given in Ref. [14][15][16][17]. Hence for intermediate values of u s from 20 to 50 mV there is trade-off between increasing effective lifetime and increasing n 0s which effect shunt noise in opposite directions and hence a peak near 45 mV.…”

Section: G-r Noise Model Including Shunt Resistancesmentioning

confidence: 99%

“…Additionally, Q ss is computed using results of standard one-dimensional model of MIS theory [13][14][15][16] …”

Section: Passivation Modelmentioning

confidence: 99%