Size and Defect related Broadening of Photoluminescence Spectra in ZnO:Si Nanocomposite Films

TL;DR

This study investigates how the size and defects in ZnO:Si nanocomposite films influence their photoluminescence spectra, revealing the importance of interface interactions and composition for broad-band emission.

Contribution

It demonstrates the role of ZnO and silicon interface in blue emission and identifies optimal conditions for broad-band photoluminescence in ZnO:Si nanocomposites.

Findings

Blue photoluminescence linked to ZnO-silicon interface

Grain size and composition critical for peak coexistence

Proper conditions enable broad-band emission

Abstract

Nanocomposite films of Zinc Oxide and Silicon were grown by thermal evaporation technique using varying ratios of ZnO:Si in the starting material. Analysis reveal the role of ZnO and amorphous silicon interface in contributing to relatively less common blue photoluminescence emissions (at $\sim$ 400 and 470nm). These blue peaks are observed along with the emissions resulting from band edge transition (370nm) and those related to defects (522nm) of ZnO. Careful analysis shows that along with the grain size of ZnO, a suitable compositional ratio (of ZnO to silicon) is critical for the coexistence of all the four peaks. Proper selection of conditions can give comparable photoluminescence peak intensities leading to broad-band emission.