Electron irradiation effects on the intersubband transitions in InGaAs/AlGaAs multiple quantum wells

Intersubband transitions in InGaAs/AlGaAs multiple quantum wells were studi ed under the influence of electron irradiation using the optical absorption technique. The intensity of the intersubband transition was dramatically d ecreased in samples irradiated with 2 MeV electron beams and doses higher t han 1 X 10(17) cm(-2). This reduction was interpreted as being due to the t rapping of the two-dimensional electrons gas in the quantum wells by the ir radiation-induced defects. The total integrated area of the intersubband tr ansition in irradiated samples was studied as a function of temperature. Th e results show that two irradiation-induced traps are involved in capturing and then releasing the confined electrons as the temperature is lowered to 77 K and then increased to 300 K. (C) 1999 American Institute of Physics. [S0021-8979(99)06501-9].