Infrared radiation-detecting device
AssigneeCalifornia Institute of Technology, a California corporation
InventorsSarath D. Gunapala, John K. Liu, Jin S. Park, True-Lon Lin, Mani Sundaram
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Abstract
An AlxGa1−xAs/GaAs/AlxGa1−xAs quantum well exhibiting a bound-to-quasibound intersubband absorptive transition is described. The bound-to-quasibound transition exists when the first excited state has the same energy as the “top” (i.e., the upper-most energy barrier) of the quantum well. The energy barrier for thermionic emission is thus equal to the energy required for intersubband absorption. Increasing the energy barrier in this way reduces dark current. The amount of photocurrent generated by the quantum well is maintained at a high level.
Claims1
A quantum well infrared photodetector, comprising:
- a plurality of periods, each period having a barrier layer and a well layer, each well layer of each period coupled between two barrier layers,
- each well having a well bottom, and a well top, and each well supporting bound energy states therein,
- materials and thicknesses of said periods being selected such that a bound energy state is substantially resonant with said well top.
Dependencies are inferred from the claim text.