Photodetector with artificial atoms of silicon

The authors demonstrate a potential application of quantum dots for the detection of photons, showing that the Coulomb interaction resulting from the capture of photoexcited carriers by quantum dots produces a detectable change in the source-drain resistance of the transistor. This quantum effect is more pronounced with higher illumination, displaying staircase quantum steps with ΔV=4 mV on the I-V characteristics at room temperature, implying that the photocurrent is increased as the light intensity is increased. The responsitivity of device is R∼3.98× 106 AW for Vd =0.18 V, and external quantum efficiency is more than 8.6%.