Tuning Schottky Barrier and Contact Type of Metal–Semiconductor in Ti 3 C 2 T 2 /MoS 2 (T = F, O, OH) by Strain: A First-Principles Study

MXene is widely used for electrode materials. However, the interfacial resistance between metal and semiconductor affects the device performance. The strain has become an effective strategy to improve interfacial properties. With the aim of revealing the interface mechanism and improving device performance, we use the first-principles calculation to investigate the electronic properties of Ti 3 C 2 T 2 /MoS 2 (T = F, O, OH) junctions and the effect of strain on the interfaces. The calculations show weak forces between Ti 3 C 2 T 2 and MoS 2 monolayer, and the interfacial interaction decreases in the order of Ti 3 C 2 (OH) 2 /MoS 2, Ti 3 C 2 F 2 /MoS 2, and Ti 3 C 2 O 2 /MoS 2 . Ti 3 C 2 F 2 /MoS 2 exhibits a p-type Schottky barrier with 0.51 eV and Ti 3 C 2 O 2 /MoS 2 shows a p-type Schottky barrier with 0.12 eV, whereas an n-type ohmic contact occurs in Ti 3 C 2 (OH) 2 /MoS 2 . Interestingly, the contact types and Schottky barrier height in the Ti 3 C 2 F 2 /MoS 2 and Ti 3 C 2 O 2 /MoS 2 junctions can be tuned by biaxial strain in plane, which shows a transition from a p-type Schottky contact to an n-type Schottky contact and then to an n-type ohmic contact. An ohmic contact is maintained in Ti 3 C 2 (OH) 2 /MoS 2 . Furthermore, the tunneling probability ( T P ) of Ti 3 C 2 (OH) 2 /MoS 2 with 27.34% drops sharply, although the T P of Ti 3 C 2 F 2 /MoS 2 and Ti 3 C 2 O 2 /MoS 2 gradually increases with increasing strain. The controllable contact type and barrier in the Ti 3 C 2 T 2 /MoS 2 junction make it a promising candidate for high-performance electronic devices.