Device modeling of HgCdTe vertically integrated photodiodes

Resistance-voltage curves of n + -on-p Hg 1Àx Cd x Te infrared photodiodes were measured in the temperature range of 60 K to 120 K. Characteristics obtained experimentally were fitted by an improved simultaneous-mode nonlinear fitting process. Based on the extracted parameters, an efficient numerical simulation approach has been developed by inserting trap-assisted and band-toband tunneling models into continuity equations as generation-recombination processes. Simulated dark-current characteristics were found to be in good agreement with the experimental data, demonstrating the validity of the nonlinear fitting process. Our work presents an efficient method for darkcurrent simulations over a wide range of temperatures and bias voltages, which is important for investigating mechanisms of carrier transport across the HgCdTe junction.

Section: Resultsmentioning

confidence: 99%

Accurate Simulation of Temperature-Dependent Dark Current in HgCdTe Infrared Detectors Assisted by Analytical Modeling

Chen

et al. 2010

“…Effects of carrier degeneracy and conduction-band nonparabolicity in HgCdTe need to be taken into account to avoid significant errors in HgCdTe device modeling. [19][20][21][22] We introduced these effects when n-type layers with doping values above $10 15 cm À3 were considered. Sentaurus Device uses Anderson's model 23 for band alignment at heterojunctions.…”

Section: Comparison Between Nonequilibrium and Equilibrium Mwir And Lmentioning

confidence: 99%

MWIR and LWIR HgCdTe Infrared Detectors Operated with Reduced Cooling Requirements

Velicu

Grein

Emelie

et al. 2010

In this work, we analyze Auger suppression in HgCdTe alloy-based device structures and determine the operation temperature improvements expected when Auger suppression occurs. We identified critical material (absorber dopant concentration and minority-carrier lifetime) requirements that must be satisfied for optimal performance characteristics. Calculated detectivity values of Auger-suppressed and standard double-layer planar heterostructure (DLPH) devices demonstrate consistently higher maximum backgroundlimited temperatures over a range of cutoff wavelengths and generally higher detectivity values achieved by Auger-suppressed detectors. Furthermore, these devices can operate with comparable performance at up to 100 K higher than DLPH detectors operating at reference temperatures above 100 K. Results of these simulations demonstrate that Auger-suppressed detectors provide a significant advantage over DLPH devices for high-temperature operation and are a viable candidate for thermoelectrically cooled detectors. Experimental dark current-voltage (I-V) characteristics between 120 K and 300 K were fitted using numerical simulations. By fitting the temperaturedependent I-V experimental data, we determined that the observed negative differential resistance (NDR) is due to Auger suppression. More specifically, NDR is attributed to full suppression of Auger-1 processes and partial ($70%) suppression of Auger-7 processes. After Auger suppression, the remaining leakage current is principally limited by the Shockley-Read-Hall recombination component. Part of the leakage current is also due to a residual Auger-7 current in the absorber due to the extrinsic p-type doping level. Analysis and comparison of our theoretical and experimental device results in structures where Auger suppression was realized are also presented.

“…(1) to (6), the sample thickness can be determined from the interference fringes in either reflection or transmission spectra for wavelengths longer than the cutoff wavelength.…”

Section: Index Of Refractionmentioning

confidence: 99%

“…The index of refraction for the wavenumber of 1100 cm -1 is calculated to be about 3.5 from Eqs. (1) to (6). From the period of Fabry-Perot oscillation for wavenumbers around 1100 cm -1 in the spectrum, the sample thickness is determined to be 7.28 µm by Eq.…”

Section: Index Of Refractionmentioning

confidence: 99%

“…The reliability of device simulators depends upon using the accurate optical absorption coefficient. 6 In this paper, we present the measured results of index of refraction and optical absorption coefficient in a range of temperatures and compositions for unimplanted and implanted HgCdTe. We compare the measured and the theoretical optical absorption coefficients and discuss the temperature dependence of the measured optical absorption coefficient at bandgap.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optical absorption of un-implanted and implanted HgCdTe

Mao

Syllaios

Robinson

et al. 1998

Self Cite

Optical absorption coefficients of un-implanted and implanted HgCdTe have been measured in a range of temperatures and compositions. The index of refraction for photon energies larger than bandgap was obtained. With the measured index of refraction, large values of the optical absorption coefficient were extracted from measured transmission spectra. The obtained optical absorption coefficient agrees very well with the Kane's model. The measured optical absorption coefficient at the bandgap linearly depends on temperature. Cutoff photon energy for highly n-type doped HgCdTe resulted from ion implantation of boron at 150 keV energy and with 1 × 10 15 cm -2 dose is larger than that for the un-implanted HgCdTe. The magnitude of the shift is consistent with the prediction of the theory of Moss-Burstein shift, using measured doping profile.