Graphene-based deep-ultraviolet photodetectors with ultrahigh responsivity using chemical vapor deposition of hexagonal boron nitride to achieve photogating

This study presents high-responsivity graphene-based deep-ultraviolet (DUV) photodetectors using chemical vapor deposition (CVD)-hexagonal boron nitride (h-BN) photogating. To improve the DUV photoresponse, h-BN was used as a photosensitizer in graphene field-effect transistors (GFETs). The h-BN photosensitizers were synthesized using CVD and then transferred onto a SiO₂/Si substrate. The behavior of h-BN irradiated with DUV light was investigated using cathodoluminescence and UV–VIS reflectance. Under 260 nm light, it exhibited a clear photoresponse with an ultrahigh responsivity of 19600 AW⁻¹, which was 460% higher than a GFET device without h-BN photosensitizers. A noise equivalent power of 3.09×10⁻¹³ W/Hz¹/2 was achieved.