Promising optoelectronic properties and potential infrared photodetection applications of two-dimensional monolayer PdTeI2

Searching for novel two-dimensional (2D) materials with excellent properties is of great importance for the design of next generation nano-devices. Based on first-principles calculations, we propose an unexplored 2D monolayer PdTeI2 material, which can be prepared from its bulk crystal by exfoliation method. Our calculations show that monolayer PdTeI2 has excellent dynamical and thermal stability. The appropriate bandgap of 0.82 eV endows monolayer PdTeI2 with superior optical absorption capacity in the infrared and visible regions. Remarkably, the in-plane electron mobility of monolayer PdTeI2 is as high as 104 cm2v- 1s � 1, which is much larger than those of most previously reported 2D materials. Based on the combination of density functional theory and non-equilibrium Green's function formalism, a large photocurrent of 40 a20/photon for photon energy of 1.0 eV is obtained under a small bias voltage in PdTeI2-based two-electrode optoelectronic devices, indicating the outstanding photoresponse characteristic of monolayer PdTeI2 in the infrared region. The large photocurrent, along with the high electron mobility and strong optical absorption make monolayer PdTeI2 a candidate material for future applications in novel optoelectronics and microelectronic devices, such as infrared photodetectors.