Optical detected magnetic resonance of nitrogen-vacancy centers in vertical diamond Schottky diode

Diamond solid-state devices are very attractive to electrically control the charge state of Nitrogen-Vacancy (NV) centers. In this work, Vertical p-type Diamond Schottky Diode (VDSDs) is introduced as a platform to electrically control the interconversion between the neutral charge NV (NV0) and negatively charged NV (NV-) centers. The photoluminescence (PL) of NV centers generated by ion-implantation in VDSDs shows the increase of NV- Zero Phonon Line (ZPL) and phonon sideband (PBS) intensities with the reverse voltage, whereas the NV0 ZPL intensity decreases. Thus, NV centers embedded into VDSDs are converted into NV- under reverse bias voltage. Moreover, the optically detected magnetic resonance (ODMR) of NV- exhibits an increase in the ODMR contrast with the reverse bias voltage and splitting of the resonance dips. Since no magnetic is applied, such a dip splitting in ODMR spectrum is ascribed the Stark effect induced by the interaction of NV- with the electric field existing within the depletion region of VDSDs.

An on-chip integrated microfiber–silicon–graphene hybrid structure photodetector

Silicon photonic devices have great potential for photocommunication, and silicon-based photodetectors have attracted wide attention. Here, we report an on-chip integrated microfiber–silicon–graphene hybrid structure photodetector that can operate in the visible and near-infrared ranges. The detector has a responsivity of ∼136 mA W−1 at 808 nm and a rise time of ∼1.1 μs. At a reverse bias of 5 V, we achieved a responsivity of ∼1350 mA W−1. Our device provides an option for on-chip integration.