Noise fluctuations in composition-graded mid-wavelength infrared photodiode from temperature and illumination

This paper is mainly centered on the nature of low frequency noise fluctuations in composition-graded HgCdTe mid-wavelength infrared (MWIR) photodiode with temperature across 80 K-300 K under dark and blackbody illumination. The results demonstrate an improvement of the Hooge parameter (5.3 × 10^-10 vs reference 5 × 10^-9) in dark noise which confirms a better device performance. Wavelength-dependent photo-induced noise characteristics show that under 420 K blackbody illumination, noise fluctuates over 3 orders, significantly exceeding under 550 K and 720 K illumination, while the anomalous noise reduction above 180 K reveals the dark current's suppression effect on photocurrent noise. These findings elucidate photo-induced noise mechanisms in MWIR detectors, providing critical insights for performance optimization through material fabrication.