Publications by authors named "Long-Hui Zeng"

In-plane anisotropic two-dimensional (2D) materials have gained considerable interest in the field of research, due to having the potential of being used in different device applications. Recently, among these 2D materials, group 10 transition metal dichalcogenides (TMDs) pentagonal Palladium diselenide (PdSe) is utilized in various sections of researches like nanoelectronics, thermoelectric, spintronics, optoelectronics, and ultrafast photonics, owing to its high air stability and broad absorption spectrum properties. In this paper, it is demonstrated that by utilizing this novel 2D layered PdSe material as a saturable absorber (SA) in an EDF laser system, it is possible to obtain switchable laser pulse generation modes.

View Article and Find Full Text PDF

Group-10 transition metal dichalcogenides (TMDs) with distinct optical and tunable electrical properties have exhibited great potential for various optoelectronic applications. Herein, a self-powered photodetector is developed with broadband response ranging from deep ultraviolet to near-infrared by combining FA Cs PbI perovskite with PdSe layer, a newly discovered TMDs material. Optoelectronic characterization reveals that the as-assembled PdSe/perovskite Schottky junction is sensitive to light illumination ranging from 200 to 1550 nm, with the highest sensitivity centered at ≈800 nm.

View Article and Find Full Text PDF

Indium selenide (InSe) has attracted tremendous attention due to its favorable electronic features, broad tunable bandgap, high stability and other attractive properties. However, its further applications for nonlinear optics have not yet been fully explored. In this work, we demonstrate that few-layer α-InSe nanosheets exhibit strong saturable absorption properties over a wide wavelength range covering 800, 1064 and 1550 nm.

View Article and Find Full Text PDF

We report on the large-scale synthesis of polycrystalline multilayer PtSe film with typical semimetallic characteristics. With the availability of the large-area film, we constructed a heterojunction composed of multilayer PtSe and Cs-doped FAPbI, which can function as a self-driven photodetector in a broadband wavelength from the ultraviolet to the near-infrared region. Further photoresponse analysis revealed that the heterojunction device showed outstanding photosensitive characteristics with a large I/ I ratio of 5.

View Article and Find Full Text PDF

Passive mode locked laser is typically achieved by the Semiconductor Saturable absorber Mirror, SESAM, saturable absorber, which is produced by expensive and complicated metal organic chemical vapor deposition method. Carbon based single wall carbon nanotube (SWCNT), saturable absorber, is a promising material which is capable to produce stable passive mode-locking in the high power laser cavity over a wide operational wavelength range. This study has successfully demonstrated the high power mode locking laser system operating at 1 micron by using SWCNT based absorbers fabricated by dip coating method.

View Article and Find Full Text PDF

Heterojunctions near infrared (NIR) photodetectors have attracted increasing research interests for their wide-ranging applications in many areas such as military surveillance, target detection, and light vision. A high-performance NIR light photodetector was fabricated by coating the methyl-group terminated Si nanowire array with plasmonic gold nanoparticles (AuNPs) decorated graphene film. Theoretical simulation based on finite element method (FEM) reveals that the AuNPs@graphene/CH3-SiNWs array device is capable of trapping the incident NIR light into the SiNWs array through SPP excitation and coupling in the AuNPs decorated graphene layer.

View Article and Find Full Text PDF

We report on the simple fabrication of monolayer graphene (MLG)/germanium (Ge) heterojunction for infrared (IR) light sensing. It is found that the as-fabricated Schottky junction detector exhibits obvious photovoltaic characteristics, and is sensitive to IR light with high Ilight/Idark ratio of 2 × 10(4) at zero bias voltage. The responsivity and detectivity are as high as 51.

View Article and Find Full Text PDF

Piperine, an alkaloid from black and long peppers (Piper nigrum Linn & Piper longum Linn), has been reported to exhibit antitumor activities in vitro and in vivo. To further understand the antitumor mechanism of piperine, we investigated the growth inhibitory effects of piperine on human prostate cancer DU145, PC-3 and LNCaP cells. Piperine treatment resulted in a dose-dependent inhibition of the proliferation of these cell lines.

View Article and Find Full Text PDF

Here we demonstrate a room temperature processed nonvolatile memory device based on an Al/AlO(x)/CdTe:Sb nanowire (NW) heterojunction. Electrical analysis shows an echelon hysteresis composed of a high-resistance state (HRS) and a low-resistance state (LRS), which can allow it to write and erase data from the device. The conductance ratio is as high as 10⁶, with a retention time of 3 × 10⁴ s.

View Article and Find Full Text PDF

A new Schottky junction ultraviolet photodetector (UVPD) is fabricated by coating a free-standing ZnO nanorod (ZnONR) array with a layer of transparent monolayer graphene (MLG) film. The single-crystalline [0001]-oriented ZnONR array has a length of about 8-11 μm, and a diameter of 100∼600 nm. Finite element method (FEM) simulation results show that this novel nanostructure array/MLG heterojunction can trap UV photons effectively within the ZnONRs.

View Article and Find Full Text PDF

Autophagic responses to chemotherapeutic agents may vary greatly among different prostate cancer cells and have not been well characterized. In this study, we showed that valproic acid (VPA) induced conversion of LC3-I to LC3-II and formation of LC3 puncta, the typical markers of autophagy, in LNCaP and PC-3 cells. However, these markers were undetectable in DU145 cells upon autophagic stimulation, indicating a defect of autophagy in this cell line.

View Article and Find Full Text PDF