Nanodevice simulations and electronic transport properties of a two-dimensional PbBr₂ monolayer

Two-dimensional (2D) wide bandgap semiconductors are promising blocks for applications in photodetections, spintronics and high energy radiation detection. Here, we probe the mechanical, biaxial strain-relate, electronic transport, and optoelectronic properties of PbBr₂ monolayer with wide bandgaps using first-principles calculations. The 2D Young's modulus of PbBr₂ monolayer is determined to be 14.68 N m⁻¹ and the shear modulus is calculated to be 5.83 N m⁻¹ at 300 K, revealing that PbBr₂ monolayer is mechanically more flexible than other 2D materials, such as hexagonal-BN and MoB₂. Interestingly, a specific forbidden bandwidth can be obtained by implementing a suitable strain on PbBr₂ monolayer, and such effect leads to indirect bandgap semiconductor properties. Furthermore, various PbBr₂ monolayer nanodevices, including p-n junction diodes, p-i-n junction field-effect transistors (FETs), and phototransistors, are designed and explored to investigate their transport properties. A variety of excellent transport properties, including prominent unidirectional transport, remarkable electrical anisotropy, obvious field-effect property, strong photoelectric response, and prominent absorption characteristics in the ultraviolet region, have been observed in these nanodevices. Our results unveil the multifunctional nature and superior performance of PbBr₂ monolayer and suggest a practical configuration for the experimental realization in next-generation semiconductor nanodevices.