Graphene Nanofilms/Silicon Near-Infrared Avalanche Photodetectors

Graphene/silicon Schottky junction diodes have been extensively studied and widely used in photodetection. However, limited to the low light absorption of single-layer graphene and bandgap of silicon, graphene/silicon devices exhibit low quantum efficiency in the infrared region. Here, we demonstrate a high-performance near-infrared Schottky diode by integrating silicon with the macroscopic assembled graphene nanofilms (nMAG). Because of the intense light absorption, low work function, and long carrier lifetime of nMAG, the device shows a detection spectra range up to 1870 nm with the responsivity of 0.4 mA/W and response speed of 371 ns. By driving the device into avalanche multiplication, 10 ⁴ -10 ⁵ of avalanche gain has been obtained, and the responsivity at 1870 nm increases to 10 A/W. The device structure in this report could be compatible with the semiconductor process so that silicon-based infrared photodetectors with high performance and low cost could be potentially realized.