Fabrication of Nanostructure CdS Thin Film on Nanocrystalline Porous Silicon

Abstract

In this work nanostructure CdS thin film with thickness 100 nm has been deposited successfully by flash evaporation technique (FET) on glass substrates at room temperature under vacuum of 10-5 mbar. XRD patterns of nanostructure CdS thin film was polycrystalline with a hexagonal structure and the preferred orientation is (002) with 2θ value about 26.25°. The value of average grain size is about 9.603 nm. The morphological properties of CdS thin film have been studied by AFM. The optical measurements indicated that CdS thin film has direct optical energy gap (Egopt) is about 4.18 eV. Nanocrystalline porous silicon (nPS) layers have been prepared during this work via electrochemical (EC) etching process of p-type silicon wafers at different etching times (10, 20 and 30) min. The morphological properties of the prepared nPS layers are studied. The Nanostructure CdS film was deposited on the porous silicon layers; this is achieved for preparation Nano-CdS/PS heterojunction solar cell. The electrical properties of prepared heterojunction have been studied in this work, that is represented by capacitance-voltage and current-voltage characteristics (under dark and illumination) characteristics for different etching times for nPS layer (10, 20 and 30 min) at room temperature.