Abstract
Group III-VI compound semiconductors are one class of important 2D-materials. The most intensively studied group III–VI material with M2X3 stoichiometry is In2Se3. Bulk In2Se3 is a typical n-type semiconductor with a direct band gap of 1.3 eV. The direct band gap of monolayer In2Se3 is about 1.48 eV. The In2Se3 flake photodetectors were broad spectra responsive from UV-visible to near infrared. In this thesis, we discuss the effect of e-beam and oxidation on In2Se3. E-beam can create defects on In2Se3, so that contact resistance rises after e-beam lithography. Oxidation reaction of In2Se3 is very fast, and InOx is p-doping to In2Se3. For In2Se3 FET, the electron mobility is up to 388 cm2/Vs at room temperature (T = 298K) for layer thickness about 10 layers. Mobility rises to 455 cm2/Vs with decrease temperature (T = 78K). For the result of illuminated measurement, we arranged the photocurrent in decreasing order: 365 nm (3.40 eV)> 530 nm (2.34 eV)> 455 nm (2.73 eV) > 635 nm (1.95 eV) > 740 nm (1.68 eV)> 850 nm (1.46 eV). In2Se3 FET have a high response to visible light, exhibiting a photoresponsivity of 11981 A/W at 530 nm with a quantum efficiency greater than 28036. Response time is 600 ms at Vgs = -40 V.