Fabrication of n-CeZnO/p-Si heterojunction diodes for enhanced solar energy conversion

Doping in semiconductor nanostructures greatly influences in their fundamental properties and greatly enhances the finale efficiencies in various applications. Here, we report the formation of n-type Ce3+ doped ZnO nano -structured thin films on p-Si wafers via a facile phytochemical assisted hydrothermal technique. The hetero-structure diodes were examined for their structural, morphological, optical, electrical and photocatalytic properties. Ce3+ ions doping in the ZnO lattices were confirmed with the change in peak position shift and the decreased crystalline size from 34 nm (pristine ZnO) to 18 nm (5% Ce3+ doped ZnO). The Ce3+ induced flake like morphology was also identified in our experiment. Further the optical bandgap values have got decreased from 3.3 eV to 2.9 eV for cerium ions doping. Measured diode parameters were sensitive to the cerium ions doping concentration besides with good rectification behaviour. Upon the light illumination enhanced current of 75% over the dark current is realized. In sunlight methylene blue dye degradation photocatalysis the n-ZnO/p-Si exhibited 45% efficiency whereas the n-CeZnO/p-Si exhibited 77%.