Graphene Field-Effect-Coupled Detection of Avalanche Multiplication in Silicon

In this work, we demonstrate the instant detection of out-of-plane avalanche multiplication in graphene-oxide-semiconductor structure via strong field-effect coupling of the graphene channel with the silicon photo gate. This in situ detection of out-of-plane avalanche can eliminate carriers’ preamplification losses in traditional avalanche multiplication charge-coupled devices (CCDs). By relying upon the electrostatic coupling, a real-time signature of the space charge region in silicon can be observed by both displacement and channel currents of the device. This allows us to alternatively probe the multiplication capability of the graphene-oxide-semiconductor structure under pulsed laser illumination while the semiconductor is dynamically biased through multiple ramping signals. The operating scheme of the device shows good capability for detecting weak light (45 nW), while the intrinsic self-regulating mechanism helps avoid oxide breakdown. The maximum multiplication factor (MF) of $\sim {10}$ , responsivity of $340 \text {A/{W}}$ , and specific detectivity of $2.85\times 10^{{13}}$ Jones are achieved, respectively.