Quantum detectors using cycling excitation process in disordered medium

Cycling excitation process (CEP) is a signal amplification mechanism showing high gain, low noise at low operation bias ^1,2 . Depending on Auger excitation that involves localized states, CEP effect may be prominent in amorphous silicon, which has abundant localized states as a disordered material. Here we present a carbon-doped amorphous Si photodiode with ultra-high gain-bandwidth product with exceedingly low excess noise factor.