Enhancing Optoelectronic Performance Through Rare-Earth-Doped ZnO: Insights and Applications

Rare-earth (RE) doping has been found to be a potent method to improve the structural, optical, electronic, and magnetic properties of ZnO, positioning it as a versatile material for future optoelectronic devices. This review herein thoroughly discusses the latest developments in RE-doped ZnO based on the role of the dopant type, concentration, synthesis method, and consequences of property modifications. The 4f electronic states of rare-earth elements create strong visible emissions, control charge carriers, and design defects. These structural changes lead to tunable bandgap energies and increased light absorption. Also, RE doping considerably enhances ZnO’s performance in electronic devices, like UV photodetectors, LEDs, TCOs, and gas sensors. Though, challenges like solubility constraints and lattice distortions at higher doping concentrations are still key challenges. Co-doping methodologies and new synthesis techniques to further optimize the incorporation of RE into ZnO matrices are also reviewed in this article. By showing a systematic comparison of different RE-doped ZnO systems, this paper sheds light on their future optoelectronic applications. The results are useful for the design of advanced ZnO-based materials with customized functionalities, which will lead to enhanced device efficiency and new photonic applications.