First-Principles Study of the Structural, Electronic, and Enhanced Optical Properties of SnS/TaS₂ Heterojunction

Abstract

Although the electronics and optoelectronics based on two-dimensional (2D) SnS have attracted great interest, their development is hindered by the large contact resistance at the interface of the metal−semiconductor junction. In this work, using first-principles calculations, we evaluate the contact performance in a van der Waals heterostructure composed of 2D SnS and TaS 2 . We demonstrate that holes can freely transfer from the electrode to the channel as a consequence of the Schottky-barrier-free interface as well as an upward band bending. Moreover, we show that the intrinsic properties of the SnS monolayer are well-preserved in the heterojunction, which is different from those of contact with metal surfaces. An enhanced optical response is also observed as compared with the freestanding sheet. Given the recent experimental synthesis of the SnS−TaS 2 superlattice, this study enhances the understanding of the interface properties of SnSbased metal contact, which is essential for future device applications.

Contact evaluation of the penta-PdPSe/graphene vdW heterojunction: tuning the Schottky barrier and optical properties

“…Next, we calculate the Schottky barrier of the penta-PdPSe/G heterojunction to determine the contact resistance in a FET device. Following the Schottky–Mott rule, 27,45 the Schottky barrier height (SBH) of electrons ( Φ e ) and holes ( Φ h ) is defined as the energy difference between the Fermi level and the respective energy band edges of the semiconductor, Φ e = E CBM − E F , Φ h = E F − E VBM where E F represents the Fermi level, while E CBM and E VBM are the band edges of penta-PdPSe identified from the projected band structure. From eqn (10), we obtain the SBH value of 0.085 eV for electrons and 0.917 eV for holes in the heterojunction from the calculated projected density of states (DOS) shown in Fig.…”

“…49 Next, we calculate the Schottky barrier of the penta-PdPSe/G heterojunction to determine the contact resistance in a FET device. Following the Schottky-Mott rule, 27,45 the Schottky barrier height (SBH) of electrons (F e ) and holes (F h ) is defined as the energy difference between the Fermi level and the respective energy band edges of the semiconductor,…”

“…26 Our previous study reported the excellent electronic and interfacial properties of a vdW heterojunction composed of SnS and TaS 2 monolayers. 27 Therefore, development of new 2D vdW heterojunctions based on novel 2D materials is scientifically desirable to make environmentally friendly and energy efficient optoelectronic applications.…”

Efficient Modulation of Schottky to Ohmic Contact in MoSi2N4/M3C2 (M = Zn, Cd, Hg) van der Waals Heterostructures

“…Here, the tunneling barrier is equated to a square potential barrier, as shown by the red box line in Figure 7e−g. The electron tunneling probability can be calculated as 66,67 i k j j j j y…”

“…Here, the tunneling barrier is equated to a square potential barrier, as shown by the red box line in Figure e–g. The electron tunneling probability can be calculated as , P TB = exp true( prefix− 2 d TB ℏ 2 m normale normalΦ TB true) where m e is the mass of the free electron; ℏ is the reduced Planck’s constant; and Φ TB and d TB are the height and width of the tunneling barrier, respectively. As shown in the Figure e–g, a large potential barrier is formed at the contact interface in the MoSi 2 N 4 /M 3 C 2 vdWHs, which hinders electron transport.…”