Polarization sensitive phototransistors based on layered germanium selenide

Atomically-thin 2D layered materials are attracting increasing attention owning to its promising potential device applications and the hosting of so many emerging electronic, spintronic and photonic properties. Among them, germanium selenide is a material exhibits strong in-plane anisotropy due to the lacking of crystal symmetry. Here, the anisotropic nature of germanium selenide is revealed by electrical transport measurement and polarization resolved Raman scattering, in which its electrical conductance and Raman intensity changes regularly when electrical contact and polarization direction of incident light changes along different crystal directions. Utilized its linear dichroism, we have successfully built phototransistors based on layered germanium selenide which shows highly responsivity photodetection of linear polarized light. The newly functionality in germanium selenide based phototransistors and exotic physical properties of it demonstrated in this study identify germanium selenide as an emerging candidate for future applications in electronic and optoelectronic devices.