HgCdTe material optimization for carrier-lifetime maximization. Final technical report, 1 September 1986-30 April 1988

Technical Report · Thu Jul 14 00:00:00 EDT 1988

OSTI ID:6661961

Vydyanath, H R

Hg(1-x)Cd(x)Te is a variable bandgap alloy semiconductor that has recently emerged to perhaps the single most-important infrared-detector material with extensive military and civilian applications. The minority-carrier lifetime in p-type base material for n(+)p photodiode structures is normally much below the radiative limit and is limited by the presence of Shockley-Read Centers, which are related to the presence of impurities and native defects in the material. In order to obtain photo diode performance close to the theoretical limits, it is essential to prepare mercury cadmium telluride material with carrier lifetime approaching radiative limit. This is possible only when the origin of the Shockley-Read Centers limiting the carrier lifetime is established and the material preparation conditions are optimized so that the concentration of these centers is reduced to a minimum. The goal of the program was to optimize the preparation conditions of the (Hg,Cd)Te material such that the carrier lifetime was maximized. Both undoped and doped crystals were investigated. To begin with, indium as an n-type dopant was investigated. At the end of the duration of the program, the material had been optimized so that the p-type carrier concentration can be controllably reproduced via anneals under well defined thermodynamic conditions, namely temperature and partial pressure of Hg., the behavior of indium-doped (Hg,Cd) Te was well established. Carrier-lifetime measurements were carried out in epitaxial HgCdTe films.

• Research Organization: Aerojet ElectroSystems Co., Azusa, CA (USA)
• OSTI ID: 6661961
• Report Number(s): AD-A-198101/8/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SEMICONDUCTOR DIODES
CARRIER LIFETIME
CADMIUM TELLURIDES
CHARGE CARRIERS
CRYSTALS
EPITAXY
IMPURITIES
MERCURY TELLURIDES
OPTIMIZATION
PHOTODIODES
PROGRESS REPORT
THERMODYNAMICS
CADMIUM COMPOUNDS
CHALCOGENIDES
DOCUMENT TYPES
LIFETIME
MERCURY COMPOUNDS
SEMICONDUCTOR DEVICES
TELLURIDES
TELLURIUM COMPOUNDS
360604* - Materials- Corrosion
Erosion
& Degradation