Ultrahigh Stability of Wearable Photodetector Using Zirconium Metal-Organic Framework Enabling In Situ and Continuous Monitoring of Ultraviolet Radiation Risk

Zirconium-benzenedicarboxylate (ZrBDC) is a remarkably stable metal-organic framework with a broadband UV absorption that would offer numerous applications related to UV detection. However, the integration of a continuous and densely packed ZrBDC film with the controllable thickness into optoelectrical devices suffers from time-consuming and complicated fabrication of ZrBDC thin film. In this study, a facile liquid-phase epitaxy method is introduced by adopting sequential and continuous layer-by-layer spin-coating technique to fabricate the high-quality ZrBDC thin film. The structural, optical, and electrical properties of the as-prepared ZrBDC thin film are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, ultraviolet-visible spectroscopy, photoluminescence spectroscopy, space charge limited current, and Mott-Schottky measurement. When ZrBDC is used as an efficient photo-absorber layer for a visible-blind UV photodetector, the device exhibits a specific detectivity of 7.85 x 10(10) Jones and rise/fall time of 80/150 ms at zero bias. Furthermore, the device reveals outstanding stability with nearly constant photoresponse during 19 h-exposure to UV illumination and after storing for 2 months, along with excellent tolerance under high operating temperature and bending strain. For practical applications, the facile estimation of UV level under sunlight is demonstrated using a wearable UV detector based on ZrBDC.