Graphene Channel Electron-Multiplying Charge-Coupled Pixel

This work presents an in-situ readout of the transient photoresponse of a graphene-oxide-semiconductor heterostructure by utilizing graphene’s field-effect coupling with the silicon photogate. The reported device which acts as a graphene charge-coupled device (GCCD) pixel is set into pre-avalanche condition by dynamic sinusoidal biasing and then exposed with pulsed illumination. The initial photo-ionized charge packet experiences pre-integration carrier multiplication, boosting the signal-to-noise ratio (SNR) before interacting with the surface traps and defects. The maximum multiplication factor of
$\mathrm {\sim }8.5$
and responsivity of
$\mathrm {350 A/W}$
are achieved. Arrhenius plots show the viability of operating the device at room temperature as thermal charge contribution is negligible. Moreover, a detailed discussion on reduced power consumption for such a sinusoidal charge-coupled device (CCD) drive concept is also incorporated. The presented technique paves the way for futuristic sinusoidally-driven graphene-silicon-based electron-multiplying CCDs with low-power surveillance and adaptive optics applications.