Intersubband Absorption Based Upon Modulation Doped Transistor Heterostructures

摘要

Intersubband absorption is reported in a new modulation doped structure using strained InGaAs quantum wells (QWs) that support transistor operation. Well defined absorption peaks (1000 cm~(-1) to 1700 cm~(-1)) from 8μm to 11.5μm have been obtained using either n- orp- type modulation doped wells. The absorption wavelength may be extended to as low as 3.2μm by using quantum dots placed within the quantum well. Both n and p well responses show strong polarization dependence with maximum values at incident angles of 65-70° and peak positions which are adjusted by the quantum well parameters. The p well shows a double peaked response with a peak separation of about 1.5μm which results from heavy and light hole contributions. A thyristor infrared detector model has been established based upon the intersubband absorption mechanism and simulation results are shown.