Ge composition dependence of photoluminescence properties of Si1−xGexSi disordered superlattices

Photoluminescence (PL) properties of Si1−xGexSi disordered superlattices (d-SLs) with various Ge compositions (x < 0.55) are studied. Thermal quenching properties and excitation power dependence of PL properties are investigated for the estimation of the disorder strength and for the assignment of the luminescence process, respectively. The red-shift energy of PL peak, PL intensity ratio I(d-SL)I(o-SL), and the characteristic temperature T0 become large by increasing the Ge composition. Improvement of the PL properties are owing to the strong hole localization effect.