Evaluation of low temperature response of HgCdTe quantum dot based MWIR FPA

This paper reports development of Mid Wave Infrared (MWIR) Focal Plane Array (FPA) using chemically synthesized Mercury Cadmium Telluride (Hg1-xCdxTe) semiconductor Colloidal Quantum Dots (CQD) coated over 320×256 pixels silicon Readout Integrated Circuit (ROIC), having significant photo-response in the MWIR spectral band (λ = 2.5µm to 5.0µm) at room temperature and variation of photo-response at lower operating temperature (120K to 260K). HgCdTe CQD has been synthesized chemically. We have characterized the optical performance of the developed sensor using calibrated Black Body Source and infrared lamps along with optical high pass filter (λCutoff = 2.1 µm) to understand its response against MWIR radiation at different operating temperature as an introductory step towards development of MWIR FPA sensitive in MWIR region and determination of optimum operating condition to achieve higher specific detectivity (D*). Optical response of the indigenously developed FPA has been evaluated inside a cryostat having optical window at different temperatures lower than ambient and peak response is found to be at T=140K.