Theoretical Design of a Multifunctional Two-Dimensional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msub><mml:mrow><mml:mi>Hf</mml:mi><mml:mi>Ge</mml:mi><mml:mi>Te</mml:mi></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:math>-Based Optoelectronic Device Utilizing the Anisotropic Photogalvanic Effect

Abstract

Achieving desirable multifunctional optoelectronic devices requires consideration of indexes such as photoelectrical response, polarization sensitivity, energy consumption, power conversion efficiency (PCE), and direction dependence. To satisfy these requirements, we propose an anisotropic ${\mathrm{Hf}\mathrm{Ge}\mathrm{Te}}_{4}$-based optoelectronic device driven by the anisotropic photogalvanic effect (PGE) for high-performance photodetection and solar harvesting. We find a robust anisotropic PGE photocurrent ${J}_{\mathrm{ph}}$ (${J}_{x}$ = 5.12, and ${J}_{y}$ = 0.07) is generated under the illumination of linearly polarized light due to the noncentrosymmetric nature of pristine ${\mathrm{Hf}\mathrm{Ge}\mathrm{Te}}_{4}$. Through appropriate mechanical bending and heterostructure assembled with a black phosphorus monolayer, the photocurrent and anisotropic ratio can be substantially enhanced by 8 times and 22.98%, respectively. Moreover, it exhibits a very high PCE of 20.19% and a large optical conductivity of about 13 \ifmmode\times\else\texttimes\fi{} ${10}^{3}\phantom{\rule{0.2em}{0ex}}{\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}1}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$. Our results show a fascinating functional coupling architecture that simultaneously implements high polarization-resolved photodetection and solar-energy harvesting in self-powered low-dimensional devices, suggesting an efficient avenue to achieve multifunctional integrated optoelectronic devices.

Topics & Concepts