Effect of magnetron sputtering parameters and stress state of W film precursors on WSe2 layer texture by rapid selenization

Abstract

Tungsten diselenide (WSe2) film was obtained by rapid selenization of magnetron sputtered tungsten (W) film. To prevent WSe2 film peeling off from the substrate during selenization, the W film was designed with a double-layer structure. The first layer was deposited at a high sputtering-gas pressure to form a loose structure, which can act as a buffer layer to release stresses caused by WSe2 growth. The second layer was deposited naturally on the first layer to react with selenium vapour in the next step. The effect of the W film deposition parameters(such as sputtering time, sputtering-gas pressure and substrate bias voltage)on the texture and surface morphology of the WSe2 film was studied. Shortening the sputtering time, increasing the sputtering-gas pressure or decreasing the substrate bias voltage can help synthesize WSe2 films with more platelets embedded vertically in the matrix. The stress state of the W film influences the WSe2 film texture. Based on the stress state of the W film, a model for growth of the WSe2 films with different textures was proposed. The insertion direction of the van der Waals gap is a key factor for the anisotropic formation of WSe2 film.

Investigation of Optimum Deposition Conditions of Radio Frequency Reactive Magnetron Sputtering of Al0.7Sc0.3N Film with Thickness down to 20 nm

“…A previous study showed that increasing pressure decreased adatom energy and the atomic peening effect, which changed in-plane stress from compressive to tensile. [46,47] Similar trend was also observed in this experiment; it showed the transition from compressive to tensile stress (between ≈5 and 10 mTorr), and further increasing pressure resulted in higher tensile stress (Figure 6b). Also, decreasing the peening effect with increasing pressure decreased the film roughness, as shown in Table S1, Supporting Information.…”

Performance analysis of WSe2-based bifacial solar cells with different electron transport and hole transport materials by SCAPS-1D

“…Recently, Hongchao Li et al. have demonstrated an environmentally friendly method to prepare WSe 2 films with different orientations on the non-conductive quartz glass [ 35 , 36 ]. Although WSe 2 thin films have many applications, such as p-n diodes [ 37 ], field-effect transistors [ 38 ], and logic devices [ 39 , 40 ], there are only a few reports that have proven its application in PV SCs so far [ 41 , 42 , 43 ].…”

Defect and interface/surface engineering synergistically modulated electron transfer and nonlinear absorption properties in MoX2 (X = Se, S, Te)@ZnO heterojunction

“…When the tensile strain is dominant, the film grows along the vertical direction of the substrate. 45,46 Here, the MoSe 2 @ZnO composite grew along the plane direction, and thus the compressive strain was greater than the tensile strain. As shown in Fig.…”