Boron tin oxide for filterless intrinsic-narrowband solar-blind ultraviolet detectors with tunable photoresponse peak from 231 to 275 nm

Solar-blind ultraviolet (SBUV) detection has a great prospect in a wide range of applications, in which the synthesis of semiconductor materials with a suitable bandgap can be an important research focus. In this work, BSnO films with good selectivity for SBUV were grown by magnetron sputtering with the bandgap adjusted from 4.1 to 5.3 eV. Based on the BSnO films, filter-less narrowband SBUV detectors were fabricated first, exhibiting a narrow detection range and an ultra-high responsivity (113 A/W) required by the detection of extremely weak SBUV signals. In addition, graphene/BSnO/SiC heterojunction photovoltaic detectors were also fabricated, with a high photo-to-dark current ratio and an ultra-fast response exhibited under 0 V bias, confirming their ability to handle the detection of transient signals.