Structural, electronic and optical properties of two-dimensional Janus transition metal oxides MXO (M=Ti, Hf and Zr; X=S and Se) for photovoltaic and opto-electronic applications

Two-dimensional MXO/MoX2 (M = Hf, Ti and X = S, Se) van der Waals heterostructure: a promising photovoltaic material

“…1). 16,47 We checked various stacking congurations of the heterostructure to explore the one with the highest stability. Hence, the phase structure of 2D materials governs the physical and chemical properties.…”

“…The PDOS ndings suggest that building an MXO and MoX 2 based heterostructure is advantageous for energy-related semiconductor materials. All monolayers of the Janus material are indirect band gap, 16,47 whereas the heterostructure MXO/MoX 2 are all obvious direct band gap semiconductors. The band gap values that were calculated for the heterostructure are listed in Table 1, except for the distorted HfSeO/MoSe 2 heterostructure, all the calculated band gap values are in the range of between 1-2 eV, indicating that the values are suitable for photovoltaic applications.…”

“…e bq jm vk * where u, the frequency of electromagnetic (EM) radiation in energy unit is U represents the volume of the primitive cell, q is the electron momentum operator, c and v are the conduction band and valence state, respectively, u k , is the k point weight E ck , E vk and m ck , m vk are the eigenvalues and wave function at the k point, respectively and e a , e b are unit vectors for the three Cartesian direction.3 Result and discussion3.1 Structural and energetic stabilities2D Janus MXO/MoX 2 heterostructures (M ¼ Ti, Hf; X ¼ S or Se) are derivatives of their TMD MX 2 counterparts (M ¼ Ti, Hf; X ¼ S or Se). MXO monolayers, like MX 2 , are composed of three atomic layers stacked in the sequence X-M-O, with the crystal structure arranged in two different ways 16,47. Hexagonal and distorted the ESI Fig.…”

“…Structural and energetic stabilities2D Janus MXO/MoX 2 heterostructures (M ¼ Ti, Hf; X ¼ S or Se) are derivatives of their TMD MX 2 counterparts (M ¼ Ti, Hf; X ¼ S or Se). MXO monolayers, like MX 2 , are composed of three atomic layers stacked in the sequence X-M-O, with the crystal structure arranged in two different ways 16,47. Hexagonal and distorted the ESI Fig.…”

2D Pentagonal Pd‐Based Janus Transition Metal Dichalcogenides for Photocatalytic Water Splitting

“…[ 24 ] In the context of photocatalytic water splitting, 2D Janus TMDs, including Janus PtSSe and Janus MoSSe monolayers, have been determined to possess highly desirable properties such as large optical absorption coefficients and suitable band edge positions with respect to the redox reactions of water, thereby rendering them promising water‐splitting photocatalysts. [ 25–27 ] In particular, double‐layer Janus PtSSe compounds exhibiting certain stacking configurations are extraordinary water‐splitting photocatalysts even under infrared light, which can be attributed to their small bandgaps and intrinsic electrical fields arising from their unique frameworks. [ 22 ] Therefore, the exclusive structures of Janus TMD monolayers may potentially endow them with exceptional water‐splitting photocatalytic properties.…”