Growth rate induced high efficient light trapping/photon conversion ZnO:Nd3+ nanodisk shaped thin films deposited by AACVD process

Abstract

This research work is a detailed study of the effect of deposition conditions on the combined light trapping and photon conversion properties of Nd3+ ions doped ZnO nanodisk thin films. Hexagonal wurtzite phased ZnO:Nd films were deposited at the temperature range of [370–500 °C] by aerosol assisted chemical vapor deposition (AACVD) process at atmospheric pressure. Actually, annealing treatment at 1000 °C in air atmosphere led to the increase of crystallinity, decrease of the porosity of the films and enhancement of their optical properties. Moreover, this work has demonstrated that annealing strongly modifies the local structure and the crystal field of the Nd3+ ions embedded in ZnO, leading to a high efficiency of visible-to-infrared downconversion (DC) emissions. The optimized 2.805 at.% Nd embedded in ZnO shaped nanodisk thin film exhibits a strong and resolved 920 and 1060 nm DC emissions. In addition, this film presents a low reflectance percentage of 17.1% with average external quantum efficiency (EQE) of 51.0% in the [400–800 nm] range, leading to an improvement of quantum efficiency of 12.5%. These findings show that the combined photon conversion and light trapping properties in semiconducting ZnO:Nd nanodisk shaped thin film is a well known passive approach that can boost c-Si solar cells efficiency.