Minority carrier lifetime in p-HgCdTe

Abstract

High operating temperature (HOT) detector concepts using midwave infrared (MWIR) (x∼0.3) p-type HgCdTe operating at temperatures within the thermoelectric cooler range are of significant interest at the present time. However, it is apparent that much work remains to be done in the areas of material, diode passivation, and diode formation technologies before the “holy grail” of photon detection at room temperature for all infrared wavelengths is achieved. Over the years, at DRS, we have developed a technology base for both n- and p-type HgCdTe materials parameters that are relevant to photodiode design and fabrication. This paper will discuss data that we have taken recently on minority carrier lifetime in MWIR and long wave infrared (LWIR) HgCdTe, particularly p type, and how it compares to current theories of Auger 7, radiative, and Shockley-Read recombination in this material. Extrinsic group IB (Cu, Au) and group V (arsenic) p-type dopants were used, together with group III (In) for n-type. The impact of the data on future HOT detector work is discussed.