Zero-bias Resistance-area Product Research Articles

High-performance 8—14- µm Pb1-xSnxTe photodiodes

Photovoltaic detectors of Pb <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</inf> Sn <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Te, sensitive in the 8- 14-µm spectral region, with near-theoretical performance characteristics, have been fabricated by a surface inversion technique. These detectors have exhibited quantum efficiencies of up to 45 percent limited by surface reflection), zero-bias resistance-area products of 21 Ωċcm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and background-limited detectivities of 1.5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> cm ċ Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> /W. A theoretical model consistent with experimental results is presented. Such high-performance devices are useful in guidance, reconnaissance, surveillance, ranging, and communication systems.

Hg-implanted Hg1−x Cdx Te infrared photovoltaic detectors in the 8- to 14-μm range

p-n junction photovoltaic detectors have been obtained by Hg implantation in Hg1−x Cdx Te for the 2- to 14-μm band. High-sensitivity photodiodes were achieved over the entire range quoted; the most interesting results are those concerning the 8- to 14-μm range; peak detectivity better than 1010 cm Hz1/2 W−1, a zero-bias resistance area product between 2.4–0.12 Ω cm2, spcific responsivity between 1.2 × 104 and 5 × 102 V W−1, and quantum efficiency between 65% and 45% were obtained.

Pb 1− xSn xTe photovoltaic diodes and diode lasers produced by proton bombardment

N- p junction photovoltaic detectors in Pb 0.88Sn 0.12Te and laser diodes in both PbTe and Pb 0.88Sn 0.12Te fabricated using proton bombardment to create the n-type layer are reported. Zero-bias resistance area products as high as 1.4 Ω-cm 2 at 77°K and 966 Ω-cm 2 at 15°K were observed for 15-mil-square Pb 0.88Sn 0.12Te photodiodes. At 77°K, peak detectivities at 7.5 μm as high as 2.5 × 10 10 cmHz1 2 /W were measured. At 15°K, the peak detectivity occurred at 10.2 μm and in reduced background was greater than 10 12 cmHz1 2 / W . Both PbTe and Pb 0.88Sn 0.12Te laser diodes operated CW at 4.2°K. The PbTe diodes exhibited single mode CW laser operation up to at least 50°K and pulsed operation up to at least 80°K.

N-p JUNCTION PHOTOVOLTAIC DETECTORS IN PbTe PRODUCED BY PROTON BOMBARDMENT

n-p junction photovoltaic detectors in PbTe have been fabricated using proton bombardment to create the n-type layer. At 77°K, zero-bias resistance area products of 300 Ω cm2 were observed for diodes with dimensions as large as 15 mil square. Peak detectivities at 5 μm in reduced background as high as 3.3×1011 cm Hz1/2/W were observed. Diode quantum efficiencies were typically greater than 30% at 5 μm.