Diamond photo-electric detectors with introduced silicon-vacancy color centers

Abstract

Color centers in diamond are promising candidates for quantum sensing in photo-luminescent or photo-electric modes. The photoinduced charge carrier separation in nitrogen-vacancy (NV) centers makes diamond an excellent visible photodetector. To date, the effect of introducing silicon-vacancy (SiV) color centers on the photo-electrical and photo-luminescent properties of diamond remains unclear. To address this issue, high-quality silicon-doped single crystal diamond (Si-SCD) photodetectors were prepared by microwave plasma chemical vapor deposition (MPCVD). It is found that an extremely low dark current of several picoamperes can be achieved with an oxygen-terminated surface. In addition, although the introduction of SiV centers enhances the device's absorption of near-ultraviolet/visible (NUV/Vis) illumination, it has little impact on the solar blind detection performance, exhibiting a responsivity of 36.2 mA W⁻¹ and detectivity of 2.10 × 10¹² jones. Meanwhile, the Si-doped detector also exhibits 10² to 10³ times higher responses to NUV/Vis signals and a faster cut-off speed. Moreover, a SiV PL enhancement of 50% was achieved with external electrical bias, demonstrating a higher electric pumping efficiency compared with polycrystalline diamond devices.