Doped ZnO in Hybrid Nanostructure for Lighting and Solar Cell Applications
Résumé
Zinc oxide (ZnO) is a wide bandgap semiconductor possessing excellent optical properties due to different types of intrinsic defects, for instance, O vacancy (VO) and Zn interstitial (Zni). The visible photoluminescence (PL) of ZnO originating from deep-level defects makes it a promising candidate for applications such as white light emitting diodes (WLEDs) and down-shifting layer for solar cells. Although it is still a controversial issue attributing visible emissions to specific defects, the environmentally-friendly nature of ZnO keeps driving the research in ZnO, in view of its potential to replace rare-earth-based phosphors as WLEDs material. [1] In our previous study, a hybrid sphere structure of ZnO nanoparticles and polyacrylic acid (PAA) matrix synthesized through a hydrolysis method has proven a noble material emitting intensively in the visible range. [2] Herein, we present a general and in-depth study of the effect of dopants in ZnO hybrid structure. Various dopants are introduced into ZnO hybrid structure in order to optimize the PL of ZnO nanoparticles. Effects of dopant nature, size and valence are investigated at different doping concentrations. The emission colour of doped ZnO nanoparticles can be tuned in visible range between yellow and green and the photoluminescent quantum yield (PL QY) can be improved by specific doping. The present work facilitates the synthesis and control of doped ZnO nanocrystals emitting from cold to warm white light.
References
[1] A. Janotti and C.G. Van de Walle. Phys. Rev. B 76, 165202 (2007).
[2] Y. Zhu, A. Apostoluk, P. Gautier, A. Valette, L. Omar, T. Cornier, J. M. Bluet, K. Masenelli-Varlot, S. Daniele, and B. Masenelli. Scientific Reports 6, 23557 (2016).