TYPE-I BAND ALIGNMENT IN SI1-XGEX/SI(001) QUANTUM-WELLS - PHOTOLUMINESCENCE UNDER APPLIED [110] AND [100] UNIAXIAL-STRESS

We present experimental verification of a type I conduction band alignment for coherently strained Si1-xGex layers in (001) silicon, with 0.15 less than or equal to x less than or equal to 0.38. A novel substrate bending scheme is used to apply in-plane uniaxial compressive and tensile stress along the [100] and [110] directions. Band edge photoluminescence from SiGe and Si is shifted with stress in accordance with deformation potential theory. Tensile stress along [110] allows clear distinction between types I and II band alignment where the predicted shifts are in opposite directions.