Eu3+-doped AlO(OH) as a spectral converter for broadband solar-blind UV photodetection

Abstract

There has been a growing interest in the application of solar-blind ultraviolet (UV) in fields including astronomy, solar energy, as well as space physics. However, efficient detection of UV in this region remains difficult for most Si-based detectors. The use of a spectral down-converter that converts solar-blind UV into visible emission that is detectable by Si-based devices has been regarded as a simple but cost-efficient strategy. Here, Eu3+-doped AlO(OH) nanoparticles, fabricated by a hydrothermal synthesis method, are demonstrated as spectral converters that converts broadband UV (from 200 to 400 nm) to visible emissions by Eu3+. In this work, the morphology and crystal phase of the Eu3+-doped AlO(OH) nanoparticles were carefully controlled to enable efficient down-conversion luminescence from Eu3+-doped AlO(OH) nanoparticles under the excitation by solar-blind UV light. A photodetector device was constructed by incorporating the Eu3+-doped AlO(OH) nanoparticles into a transparent organic/inorganic composite thin film (AlO(OH): Eu3+-PMMA) that is coated onto a Si-based photosensitive resistance. An efficient photo-voltage response was observed by using an oscilloscope under broadband solar-blind UV irradiation from 200 nm to 400 nm. The results reveal a prospective strategy for the design of detectors operating in the solar-blind UV region.