HgCdTe photodiodes with cutoff wavelengths of 17 mu m at 70 K for use in high resolution interferometers for remote sensing

Traditionally, photoconductive (PC) HgCdTe detectors have been used in interferometers for detection in the 14-15 mu m range. In this paper we present recent quantum efficiency and junction impedance data which demonstrate that P-on-n HgCdTe photovoltaic (PV) detectors with 16-17 mu m cutoff wavelengths at 70 K ate suitable for use in spaceborne remote sensing interferometric instruments such as IMG-2, ATRAS, TES and CCOSM. The performance of these large-area detectors is of particular importance for interferometers because they have higher linearity at higher fluxes than PC HgCdTe arrays. The linearity requirement of 1% for the IMG-2 instrument, with background fluxes in excess of 10(16) ph/cm(2)-s, is only marginally met by PC HgCdTe detectors. We present, for the first time, data showing better than 1% linearity at fluxes of 1.3x10(17) ph/cm(2)-s for PV HgCdTe detectors with 60 K cutoff wavelengths of 15.5 mu m.