Investigation of a noise source and its impact on the photocurrent performance of long-wave-infrared InAs/GaSb type-II superlattice detectors

Abstract

Electrical noise significantly limits the detectivity of infrared photodiode detectors. In this paper, we investigated the dark current and noise spectra for long-wave-infrared InAs/GaSb type-II superlattice (T2SL) detectors to study the origin of noise under various work conditions. The temperature-dependent I-V characteristics reveal a turning point near 90 K, below which the dominant dark current mechanism changes from Shockley-Hall-Read generation current and diffusion current to shunt current and trap-assisted tunneling (TAT) current. The contribution of shunt and tunneling process to the total 1/f noise are analyzed by fitting the noise power spectral density at 77 K for detectors. It is found that the TAT current dominates the 1/f noise at the reverse bias stronger than -0.1 V, while shunt current exhibits a larger contribution at the reverse bias less than -0.1 V with the shunt noise coefficient αshunt of 5×10−8. Furthermore, the leakage routes related to the shunt process and their temperature dependence are illustrated by two-dimensional photocurrent mapping.

The Role of Noise in Specific Detectivity of InAs/GaSb Superlattice MWIR Bariodes

“…In this paper, all noise characteristics are shown in the HOT temperature range in addition to the low-temperature characterization. Furthermore, to the best of our knowledge, there are no low-frequency noise measurements reported for bariodes on GaAs substrate, in contrast to recently reported results for various detectors on GaSb substrate [19,21,22].…”

“…Different values of noise coefficient α sh = S i (f = 1 Hz)/(I sh ) 2 , related to the shunt current, have been reported in the literature. For InAs/GaSb SL devices, α sh is within the range of 3 × 10 −10 -6 × 10 −6 Hz −1 [21,27]. Our values of α sh lie in the middle of that range and change with the temperature only slightly.…”

“…In the high-temperature region, the diffusion and generation-recombination currents dominate the total current. It was shown that such current, especially the diffusion component, has a much lower noise coefficient [18,21,[27][28][29]. For detectors with InAs/GaSb SL absorber, α g-r = 4.8 × 10 −9 Hz −1 and α diff = 1.9 × 10 −10 Hz −1 were found for generation-recombination and diffusion current, respectively [19].…”

Investigation of Low Frequency Noise-current Correlation for the InAs/GaSb T2SL Long-wavelength Infrared Detector

“…However, there is no a universal model to forecast the exact 1/f noise value for a given detector. In the 1/f noise research, the most usual method which is also applied in this study is the Hooge model [14], by this model, the individual contribution of each dark current to the total 1/f noise can be expressed as the following formula where (f) means the total 1/f noise power special density (PSD), Ik is the k-component of the dark currents that have contribution to the total PSD. αk and βk are the noise coefficient and the current exponent of k-component, respectively.…”

Multi-technique characterisation of InAs-on-GaAs wafers with circular defect pattern

“…For A III B V semiconductor compounds, especially 6.1 Å-family materials, there has also been great progress in uniformity improvements and mapping techniques developments. Many recent research studies on thick layers of arsenides (e.g., InAs, GaAs), antimonides (e.g., InSb, GaSb), and their ternary alloys (e.g., InAs1-xSbx) [20][21][22][23], as well as low-dimensional structures composed of aforementioned compositions, like quantum dots (QDs) [24][25][26], nanowires [27,28], quantum-well infrared photodetectors (QWIPs) [29], or type-II superlattices (T2SLs) [30][31][32], indicate strong interest in the topic. Considering mapping, the aim is to obtain as much information as possible using non-destructive techniques.…”