Low Noise, High Gain-Bandwidth Photodetectors Using Cycling Exciting Process (CEP) as Amplification Mechanism

We report a new physical mechanism, cycling excitation process (CEP), that produces intrinsic gain for photocurrent. The CEP process has shown much greater efficiency and lower noise than the impact ionization process, the mechanism for avalanche photodetectors. Using the CEP process, we have obtained detectors of low excess noise and a record high gain-bandwidth product of over 2 THz. Above all, such performance was obtained from a thin (30nm) layer of amorphous silicon as the gain medium.