Highly Efficient Broadband Solar‐Blind UV Photodetector Based on Gd2O3:Eu3+–PMMA Composite Film

Abstract Due to their broad applications in civil and military fields, solar‐blind ultraviolet (UV) photodetectors have been paid with growing interest in recent years. Among lots of emerging materials exploited as spectral convertors for such photodetectors, rare‐earth (RE) ion‐activated downconversion (DC) materials show high quantum efficiency under UV excitation. However, up to date, RE ion‐based DC materials for solar‐blind UV converting photodetector can only enable UV detection in a narrow spectral region based on different device configurations. Herein, a highly efficient broadband solar‐blind UV photodetector constructed by coating a silicon‐based photosensitive resistor (Si‐BPR) with a transparent polymer composite film containing Gd 2 O 3 :Eu 3+ particles is presented. In the design, Gd 2 O 3 :Eu 3+ phosphor particles with efficient UV‐excited DC luminescence are mixed with poly(methyl methacrylate) to form a transparent composite film, which serves as an effective spectral converter for the conversion of broadband solar‐blind UV light to visible light, and this downconverted visible light can ultimately be absorbed by Si‐BPR to produce photoresponse. The result provides a facile approach for highly efficient broadband solar‐blind UV detection and may enable novel applications of RE‐activated hybrid luminescent films.