Electrical Transport Mechanism in Au Modified Nano Porous Silicon

Electrical Transport Mechanism in Au Modified Nano Porous Silicon

Nano porous silicon (PS) has drawn considerable attention as a potential material for different sensors and other device applications. A metal modified PS can be of certain scientific and practical interest in order to control its high intrinsic resistivity and current transport through it to make it an efficient electronic device material. We present here a study on the electrical transport in Au-modified nano PS layers obtained by anodic etching of p-Si with in-situ Au nano-particle incorporation from the dissolved Au salt in the etching solution. The current-voltage characteristics of the resulting Au-modified PS layers have been studied with reference to the unmodified PS layers. The results suggest that direct tunnelling is the dominating charge transport mechanism in Au-modified PS layers. With the increasing Au concentration, electrical transport mechanism deviates slowly from the hopping type in low applied field, Poole-Frenkel type in moderate applied field and Fowler-Nordheim type in high applied field range as observed in case of un-modified PS layers.