Highly Sensitive Photovoltaic-Type DUV Detector Based on SnO₂ Quantum Dots

Quantum dots (QDs) deep ultraviolet (DUV) photodetectors have attracted extensive attention due to their facile solution processability in recent years. Besides, photovoltaic photodetectors have shown excellent performance that they can work without external bias and have a fast response speed. Based on this situation, we construct a p-i-n (p-graphene/SnO2 QDs film/n-SiC) structure DUV photovoltaic detector with SnO2 QDs film being the DUV sensitive layer and getting connected with wet-transfer p-graphene and n-SiC substrate. Under 0-V bias, the responsivity of this device can reach 8.22 mA/W under the illumination of 255-nm DUV with 23.2- $\mu \text{w}$ /cm2 optical power density. Furthermore, the rise/decay time of the device is 170/290 ms, respectively, and ${I}_{\text {photo}}/{I}_{\text {dark}}$ can reach 228. This work provides a suitable way to fabricate low-cost DUV photovoltaic detectors.