Strain-Enhanced Responsivity of Scalable and Flexible Diamond UV Detector

In this letter, we present scalable and flexible diamond UV detectors. A 2-inch, 1- $\mu $ m-thick diamond film is exfoliated from its heteroepitaxial silicon substrate and transferred to a soft PDMS substrate, forming the foundation for the flexible detector. Measurement under strains of 0%, 0.6%, and 1.2% reveals a decrease in the bandgap of diamond film from 5.31 eV to 5.18 eV and 5.06 eV, respectively. This strain-induced narrowing of the bandgap improves the responsivity of diamond detectors under UV illumination. The elastic strain engineering on diamonds, being simple and effective, provides a new route to improve the performance of diamond UV detectors, promising to accelerate the development of next-generation flexible diamond electronics.