[19p-Z22-1~16] 3.13 Semiconductor optical devices

▲ [19p-Z22-13] Enhancement of the Ge sub-bandgap photo-response at 2-μm band by photo-gating effect

〇(DC)Ziqiang Zhao¹, Kasidit Toprasertpong¹, Shinichi Takagi¹, Mitsuru Takenaka¹ (1.The Univ. of Tokyo)

Keywords:semiconductor, germanium, phototransistor

Mid-infrared (MIR) spectrum covers a wide-range of molecular fingerprint wavelengths that is suitable for advanced sensing technologies. Germanium (Ge) is expected to be an ideal material for its superior electrical and optical properties in MIR spectra. In this work, we demonstrated a Ge phototransistor utilizing the defect-assisted photon absorption and photo-gating effect that will be useful for molecular sensing. An enhancement factor of approximately 1,300 at 4 V bias-voltage was obtained for a Ge phototransistor as compared with Ge photodiode.