BARRIER-CONFINEMENT-CONTROLLED CARRIER TRANSPORT INTO QUANTUM WIRES

By using subpicosecond laser light pulses with a polarization perpendi cular to deep etched In0.53Ga0.47As/InP quantum wires, initial spatial electron-hole distributions have been prepared that are predominantly located in the unpatterned InP buffer layer. Under these excitation c onditions the photoluminescence rise time increases significantly with decreasing wire width from about 25 ps for a two-dimensional unetched reference structure to about 150 ps for 34-nm-wide wires. Temperature -dependent studies of the rise times indicate the existence of an effe ctive barrier in the InP regions of the quantum wires. From detailed c alculations of the electronic states, which extend from the unpatterne d InP buffer into the quantum wires, we show that confinement effects in the InP barriers control the carrier transport from the buffer into the In0.53Ga0.47As wire.