Fabrication and high photoresponse performance of a La-doped HfO2 2 thin film-based UV photodiode

The ability to detect ultraviolet light is crucial for various applications such as energy harvesting, environmental monitoring, sensing, and ultraviolet astronomy. In this paper, we determined the photoelectric properties of a photodiode based on an interfacial layer of a La-doped HfO2 2 (HfLaO) thin film. We carried out several tests to analyze the electrical behavior and photoresponse of the Au/HLO/p-Si photodiode under ultraviolet (UV) and white light illumination and in the dark. The chemical composition, surface morphology, cross-sectional thickness, optical properties, and crystalline structure of the HfLaO (HLO) film prepared by the sol-gel method were characterized. We found that the prepared photodiode exhibited excellent repeatability and stability. Moreover, the photocurrent increased with increasing UV light intensity. When the UV light intensity was 23.5 mW/cm2, 2 , the photocurrent reached 700 mu A and remained unsaturated at a 7 V bias voltage. Moreover, we systematically analyzed the changes in the energy bands and carriers under dark and ultraviolet light conditions to further understand the working mechanism of the photodiode. Overall, the Au/HLO/p-Si photodiode had excellent ultraviolet detector performance and could be a strong candidate for optoelectronic applications.