Orientation- and Electrode-Dependent Electronic Transport and Photoresponse in Janus PtSSe Transistors

Two-dimensional (2D) Janus materials with their inherent structural asymmetry offer a distinctive platform for exploring diverse interfacial phenomena in electronic and optoelectronic devices. Nevertheless, the correlation among device performance, electrode layout, and crystallographic orientation remains insufficiently studied. Herein, six distinct Janus PtSSe-based devices are designed, exhibiting a strong dependence of electrical transport and photodetection properties on the electrode layouts and orientation. By altering the graphene layout between S_Gr and Se_Gr, a reversal switch can be found in the direction of rectification and photocurrent. Additionally, the device with S (Se)_Gr contacts exhibits superior electrical rectification and photodetection performance compared to that with S_Gr_Se contact, and the highest rectification ratio and photocurrent density along the zigzag direction of the S_Gr contact is up to 1.2 × 10⁹ and 54.70 nA/m, respectively. Especially, a transition of S (Se)_Gr contacts to S_Gr_Se contact can cause the electrical transfer characteristics from the n-type to the unique bipolar type. This work provides valuable insights into the multidimensional applications of Janus materials and electrode layouts in programmable optoelectronic devices.