Electronic transport characteristics and nanodevice designs for β-HfNCl monolayer

摘要

The mechanical properties, electronic structure, electric transport and optoelectronic properties of a recently predicted wide bandgap semiconductor fl-HfNCl monolayer are systematically studied by means of firstprinciples calculations. fl-HfNCl monolayer is isotropic in mechanical properties, whose calculated Young's modulus, shear modulus, and layer modulus of fl-HfNCl monolayer are 128.9-129.2, 44.28, and 119.46 N m-1, respectively. An appropriate tensile strain (i.e., beyond 3 %) can induce a transition from indirect bandgap to direct bandgap. In addition, we construct several conceptual nanodevice structures based on fl-HfNCl monolayer, such as pn-junction diodes, pin-junction field-effect transistors (FETs) and phototransistors. The electronic transport results reveal that the pn-junction diodes have obvious rectification effect and strong electric anisotropy. Their rectification ratios and electric anisotropy ratio (q) can reach up to 106 and 3.69, respectively. The FETs have an obvious field-effect behavior with a slightly lower rectification ratio (105). Moreover, we investigate the photoelectric response of the phototransistors of fl-HfNCl monolayer under the illumination of light. They have a strong response to the light whose energy is larger than the violet light, indicating that the fl-HfNCl monolayer can be a platform to detect the ultraviolet light. These findings provide crucial insights into the potential applications of fl-HfNCl monolayer in electronic and optoelectronic devices.

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