InGaAs base infrared hot-electron transistors

An infrared hot-electron transistor with a thin (300 AA) InGaAs base layer is constructed. The transistor structure increases the detectivity of a state-of-the art quantum well infrared photoconductor (QWIP) by a factor of two at 77 K, provides a photovoltage gain of 9.7 and a power gain of 3.2, reduces the noise equivalent temperature difference of a detector array by a factor of 36, and can be used for quasi-photovoltaic operation. Using the transistor structure as an analytical tool, the photoelectron transport properties of a QWIP can be extracted, based on which a quantitative theory for the photoconductive gain can be established.<>