Photocurrent Effect in Reverse-Biased p-n Silicon Waveguides in Communication Bands

The photocurrent effect in reverse biased p-n silicon waveguides at wavelength 1550 nm is experimentally investigated. The photocurrent, which is mainly related to surface-state absorption, defect-state absorption and/or two-photon absorption, is more than 0.08 µA/mm under 8 V reverse biasing and 0.75 mW irradiation. The responsivity of a silicon waveguide with length of 4500 µm achieves 0.5 mA/W. Moreover, the enhancement of the photocurrent effect under the electric field is discussed.