1/f noise and specific detectivity of HgCdTe photodiodes passivated with ZnS-CdS films

1/f noise in HgCdTe photodiodes has been measured as a function of temperat ure, diode bias, and dark current. The dependence of 1/f noise on dark curr ent was measured over a wide temperature range. At low temperatures, where surface generation and leakage current were predominant, a linear relations hip between 1/f noise and dark current was observed. At higher temperatures , where diffusion current is predominant, the correlation no longer holds. The temperature dependence of 1/f noise was also determined, The temperatur e dependence of the 1/f noise was found to be the same as that for the surf ace generation and leakage currents. All the data obtained in these experim ents could be fit with theoretical predictions by a simple relationship bet ween 1/f noise and dark current. The 1/f noise in the HgCdTe photodiode var ies with diode bias, temperature, and dark current only through the depende nce of the surface current on these devices. The maximum specific detectivi ty (D*) value and the maximum signal-to-noise ratio are approximately 3.51x 10(10) cm.Hz(1/2)/W and 5096 at 50 mV reverse bias, respectively.