Temperature-sensitive mechanism for silicon blocked-impurity-band photodetectors

Benefit from high quantum efficiency and low dark current, blocked-impurity-band (BIB) detectors have been the state-of-the-art choice in astronomy science. The temperature extrinsic-response-reduction mechanism in BIB detectors is vague for lack of pertinent research. We fabricated Si:P BIB detectors with a remarkable blackbody detectivity of 2 × 1012 cm · Hz1/2/W at 4 K, 2 V (blackbody 800 K). Both varying temperature optoelectronic characterization and calculated results overturn the common standpoint that focuses on ionization proportion. Instead, solid evidence indicates that the increase in the negative charge density according to temperature significantly influences the width of the depletion region until it totally vanishes beyond 20 K. The mechanism enriches the design thoughts of the BIB detector for improving its performance.