ABSTRACT
Understanding the mechanism of the negative differential resistance (NDR) in transition metal dichalcogenides is essential for fundamental science and the development of electronic devices. Here, the NDR of the current-voltage characteristics was observed based on the glutamine-functionalized WS2quantum dots (QDs). The NDR effect can be adjusted by varying the applied voltage range, air pressure, surrounding gases, and relative humidity. A peak-to-valley current ratio as high as 6.3 has been achieved at room temperature. Carrier trapping induced by water molecules was suggested to be responsible for the mechanism of the NDR in the glutamine-functionalized WS2QDs. Investigating the NDR of WS2QDs may promote the development of memory applications and emerging devices.
ABSTRACT
This research investigates the electro-optical properties of reverse mode liquid crystal gel (LC-gel) scattering films. The LC-gel has been fabricated through the fibrous self-assembly of the gelator 12-hydroxydodecanoic acid (G12) and mesogen monomer (RM257) in nematic LC HTW106700-100 (HTW). Adding RM257 monomer improves the transparency in the OFF state and enhances scattering effects in the ON state. Moreover, an extremely low switching voltage (â¼ 1 V) is demonstrated.
ABSTRACT
This paper investigates the effects of ZnO nanoparticles (NPs) on the switching voltages of polymer dispersed liquid crystal (PDLC) films. The threshold and driving electric fields of PDLC film doped with 2.44 wt% ZnO NPs were 0.13 and 0.31 V/µm, respectively, with a contrast ratio of 26. The results of field emission scanning electron microscopy show that the size of the droplets in doped PDLC films increases with the doping concentration. The development of ZnO-doped PDLC films with low driving voltages greatly broadens the applicability of these devices.
ABSTRACT
We investigated the optical properties of a one-dimensional photonic crystal infiltrated with a bistable chiral tilted homeotropic nematic liquid crystal as the central defect layer. By modulating the nematic director orientation with applied voltage, the electrical tunability of the defect modes was observed in the transmission spectrum. The composite not only is a general tunable device but also involves the green concept in that it can operate in two stable states at 0 V. Under the parallel-polarizer scheme, the spectral characteristics suggest a potential application for this device as an energy-efficient multichannel optical switch.
ABSTRACT
This study presents and demonstrates an approach for determining the surface tilt angles of parallel-aligned liquid crystal cells. The relationships between the incident angles and the corresponding phase retardations in the splay and the bend configurations are analyzed. The equations for the surface tilt angles are derived accordingly, and their accuracy is discussed. This method does not require knowledge of the cell thickness and is easily applied to assembled pi-cells.