Intersubband absorption performed on p-type modulation-doped Si0.2Ge0.8/Si quantum wells grown on Si0.5Ge0.5 pseudosubstrate

Abstract

We present intersubband absorption measurements performed on p-type quasistrain-compensated modulation-doped Si0.2Ge0.8/Si quantum wells grown on Si0.5Ge0.5 pseudosubstrates. Several intersubband absorption peaks are observed up to room temperature. A strong confinement shift of the resonance occuring between the ground and the first excited heavy hole states has been observed, with the absorption peak shifting from λ=5.3μm to as short as 3.8 μm. Excellent overall agreement with a 6 band kp calculation is obtained, proving the accuracy of recently predicted values of band offsets.