Large scale fabrication of well-aligned CdS/p-Si shell/core nanowire arrays for photodetectors using solution methods.

We report a facile approach for the preparation of the vertically aligned, large scale CdS/p-Si shell/core nanowire heterojunction arrays based on successive ionic layer adsorption and reaction deposition. The results indicate that the rectifying characteristics of CdS/Si shell/core nanowire arrays can be tailored by changing the number of SILAR cycles, and the CdS/Si shell-core nanowire heterojunctions have good photo-sensitivity (the ratio of photocurrent to dark current could reach 14.96 at -1 V reverse bias) under AM 1.5 (1 Sun) illumination. Furthermore, the electron transport mechanism across the CdS/Si nano-heterojunctions is also discussed in detail. This reported CdS/p-Si shell/core nanowire structure offers a generic approach for the integration of new functional materials for photo-electronics applications.