Self-organized nanoclusters of semiconductor compounds on vicinal Si surfaces and its influence on carrier recombination in Si

The self-organized nanocluster ensembles of ZnSe, CdSe and PbS were grown by laser ablation on vicinal Silicon (111) surfaces. The properties of the layers were investigated by XPS (X-rays photoelectron spectroscopy) and Auger spectroscopy. The properties of the semiconductor-clustered layer on single Si crystal structure were investigated by deep level transient spectroscopy (DLTS) and by microwave absorption induced by light pulse excitation. The clustered layer and multilayer structure modified the recombination at the Si surface and created additional carrier capture centres. Absolute values of surface recombination rate, s, were determined by the method of asymptotic lifetime amplitude. An increase of s is caused by formation of PbS clusters, while for CdSe clusters, this dependence was found to be weaker. Structures with barriers or flat conduction bands were grown on the silicon surface using different doping concentrations of layers.