Giant bulk photovoltaic effect driven by the wall-to-wall charge shift in WS2 nanotubes

Abstract

The intrinsic light–matter characteristics of transition-metal dichalcogenides have not only been of great scientific interest but have also provided novel opportunities for the development of advanced optoelectronic devices. Among the family of transition-metal dichalcogenide structures, the one-dimensional nanotube is particularly attractive because it produces a spontaneous photocurrent that is prohibited in its higher-dimensional counterparts. Here, we show that WS2 nanotubes exhibit a giant shift current near the infrared region, amounting to four times the previously reported values in the higher frequency range. The wall-to-wall charge shift constitutes a key advantage of the one-dimensional nanotube geometry, and we consider a Janus-type heteroatomic configuration that can maximize this interwall effect. To assess the nonlinear effect of a strong field and the nonadiabatic effect of atomic motion, we carried out direct real-time integration of the photoinduced current using time-dependent density functional theory. Our findings provide a solid basis for a complete quantum mechanical understanding of the unique light–matter interaction hidden in the geometric characteristics of the reduced dimension.

Heteroatoms (Si, B, N, and P) doped 2D monolayer MoS2for NH3gas detection

“…Molybdenum disulde (MoS 2 ) a 2D transition metal dichalcogenide (TMD), has attracted great scientic interest due to its intrinsic band gap compared to 2D materials like graphene which has a zero band gap. 1,2 Due to the intrinsic band gap of MoS 2 and its optoelectronic properties, it has been found to have interesting characteristics, such as high sensitivity, fast response, high selectivity, good reliability, quick recovery, high specic surface area, good chemical stability, high thermal stability and high surface activity compared to other 2D materials. These features and many more have drawn the attention of the sensor community towards MoS 2 and its dopants as promising sensor materials in detecting various environmental gases.…”

Mesoscopic sliding ferroelectricity enabled photovoltaic random access memory for material-level artificial vision system

“…In the previous study, asymmetric van der Waals layers were shown to induce shift current and generate photovoltaic effect with fixed direction 33 , 46 . The shift current is an important physical mechanism to generate the bulk photovoltaic effect with a fixed direction 47 . The photovoltaic effect in this work, which is programmable in both direction and magnitude by bias, should be dominated by a different mechanism.…”

Optoelectronic Manifestation of Orbital Angular Momentum Driven by Chiral Hopping in Helical Se Chains

“…Here x̂and ŷare the position operators along the x-and y-axis, respectively, and S ̂z is the SAM operator along the z-axis. To estimate the carrier density of states (CDOS) in Figure 2e and the nonequilibrium carrier weight (W n,k ) in Figure 2g, we projected the time-evolving wave function onto the unperturbed ground states as below: 62,63 Ä…”

“…61,62 where n is the band index; f n,k is the initial occupation of the Bloch state; and m e is the mass of an electron.…”