Tuning the Electronic and Optical Properties of the ZrS₂/PtS₂ van der Waals Heterostructure by an External Electric Field and Vertical Strain

Abstract

Two-dimensional (2D) material-based heterostructures gain increasing interest due to their extraordinary properties and excellent potential for the optoelectronic devices. This study deals with modulation of electronic and optical properties of the ZrS 2 /PtS 2 van der Waals heterostructure under vertical strain and an external electric field based on first principles calculation. Different stacking of ZrS 2 and PtS 2 layers are considered for the heterostructure formation and the most stable structure with lowest binding energy is selected for further calculations. The stable ZrS 2 /PtS 2 heterostructure shows an indirect band gap of 0.74 eV, which is smaller than that of both ZrS 2 and PtS 2 monolayers. With the applied external electric field, the band gap value of the ZrS 2 /PtS 2 heterostructure increases with the negative electric field and decreases with the positive electric field. It is observed that the indirect-to-direct band gap transition occurs when the highest negative value of the electric field is applied. In the case of vertical strain applied to the heterostructure, with an increase in compressive strain, the band gap decreases and vice versa for tensile strain. Optical absorption spectra show significant absorption in the visible light region to the ultraviolet light region. This study shows that the electronic and optical properties of ZrS 2 /PtS 2 heterostructures can be modulated by using vertical strains and an external electric field.

2D Janus ZrSSe/SnSSe Heterostructure: A Promising Candidate for Photocatalytic Water Splitting

“…The transition metal dichalcogenides (TMDs), specifically MX 2 (where M = Zr, Sn; X = S, Se), exhibit semiconducting characteristics in their 1T-phase. 31 These structures adopt a 1T-CdI 2 -like configuration with the P 3̅ m 1 space group, where the M atom is situated between two chalcogen atoms (X = S, Se), forming a single atomic layer within the trigonal structure. 32 In bulk TMDs, a layered structure is observed where each layer mirrors its adjacent layer, and weak van der Waals interactions prevail between the layers.…”

Solar energy harvesting by a PtS2/ZrS2 van der Waals heterostructure

“…In our computation of electronic properties, these obtained results support the previously reported data with the PBE functional but in order to get more accurate results we have used the HSE functional. 51,52…”

“…In our computation of electronic properties, these obtained results support the previously reported data with the PBE functional but in order to get more accurate results we have used the HSE functional. 51,52 The work function of the material is defined as the amount of energy required to remove an electron from the surface, which is calculated using formula (7), 53 where the terms E f and E vac correspond to the Fermi energy and electrostatic potential relative to the vacuum, respectively, and work functions of ML PtS 2 , ML ZrS 2 , and v-HS PtS 2 /ZrS 2 are illustrated in Fig. 4(a)-(c) respectively.…”