Suppressed Fermi Level Pinning and Wide-Range Tunable Schottky Barrier in CrX3 (X = I, Br)/2D Metal Contacts

CrX3 (X = I, Br) monolayers exhibit outstanding performance in spintronic devices. However, the Schottky barrier at the CrX3/electrode interface severely impedes the charge injection efficiency. Herein, we propose two-dimensional (2D) metals as electrodes to form van der Waals (vdW) contact with CrX3 monolayers and systematically explore the contact properties of CrX3/metal by density functional theory (DFT) calculations. The results demonstrate that the strongly suppressed Fermi level pinning (FLP) effect and the wide-range tunable Schottky barrier can be achieved in CrX3/metal contacts. Specifically, the n-type and the p-type Schottky contacts can be realized in CrX3/metal contacts by choosing 2D metal electrodes with different work functions. Importantly, the pinning factors for CrX3/metal contacts are exceptionally larger than other commonly studied 2D semiconductors, indicating the strongly suppressed FLP in CrX3/metal contacts, which leads to the wide-range tunable Schottky barrier. Our findings provide guidance to the choice of electrodes and promote the development of CrX3-based spin devices.

Automated summary

By using density functional theory calculations, it is found that the use of 2D metals as electrodes can effectively suppress the Fermi level pinning effect and achieve tunable Schottky barrier in CrX3 (X = I, Br) monolayers. These findings are important for electrode selection and the development of CrX3-based spin devices.