HgCdTe Quantum Dot Over Interdigitated Electrode for Mid-Wave Infrared Photon Detection and Its Noise Characterization

Abstract

In this paper, we report the development of mid-wave infrared (MWIR) photon sensor using solution-processed mercury cadmium telluride (Hg[Formula: see text]CdxTe) semiconductor colloidal quantum dots (CQDs) coated over interdigitated metallic electrode structure, having significant response in the MWIR spectral band range ([Formula: see text]–5.0[Formula: see text][Formula: see text]m) at room temperature. HgCdTe CQD has been chemically synthesized. We have characterized the optical and [Formula: see text] noise performances of the developed sensor to understand its behaviors at different operating biases as an introductory step toward development of large-format MWIR focal-plane arrays having similar pixel structure. The optimum biasing conditions have been experimentally evaluated at room temperature. We have achieved a noise equivalent power (NEP) of 2.5[Formula: see text]pW at 1.5-V bias voltage which corresponds to detectivity ([Formula: see text]) in the order of 108. This work highlights the development of low-cost colloidal HgCdTe quantum dot photodetectors and their utility in the monolithic infrared focal-plane arrays.