PHOTOLUMINESCENCE AND MAGNETOTRANSPORT OF 2-D HOLE GASES IN SI/SIGE)SI HETEROSTRUCTURES

p-Type modulation-doped Si/Si1-xGex/Si strained layer double heterostructures with x approximately 0.2 have been epitaxially grown on (100) Si substrates using low pressure chemical vapor deposition (LPCVD). The modulation doping effect has been obtained by two remote boron-doped Si layers approximately 10 nm thick. Hole mobilities as high as 5900 cm2/Vs have been obtained at 4.2 K comparable to the best reported values, so far. The temperature dependence of the 2-D hole concentration and mobility shows characteristic remote ion-dominated scattering. Clear quantum Hall plateaus and Shubnikov-de Haas oscillations were observed. The photoluminescence (PL) from the SiGe quantum well (QW) shows excitonic behaviour in its variation with excitation power. A general trend of increasing PL intensity with the mobility of the 2-D hole gas was observed. The high hole mobility and strong PL reflect the good interfacial quality of the LPCVD Si/SiGe/Si heterointerfaces.