Zhide Han

Excellent dielectric properties of polymer composites based on core-shell structured carbon/silica nanohybrid

Polymer based composites with high dielectric constant and low dielectric loss were fabricated by dispersing core-shell structured carbon/silica nanohybrid (CS) into a poly (vinylidene fluoride) (PVDF) matrix. Due to the high conductive carbon core, nonconductive silica shell and the good dispersion of the CS fillers in PVDF, the CS/PVDF composites exhibited better dielectric properties than most nano-carbon materials/polymer composites. These experimental results can be understood by the percolation theory and microcapacitor model. Our strategy provides a pathway to achieve nano-carbon materials/polymer composites with good dielectric performances.

Fullerene filling modulates carbon nanotube radial elasticity and resistance to high pressure

The high pressure behavior of carbon nanotubes (CNTs) filled with fullerenes (C60@CNTs) is investigated systematically using molecular mechanics and molecular dynamics simulations. It is shown that the C60 filling can increase the transition pressure (Pc) of intrinsic CNTs and optimize the radial elasticity of CNTs. The C60 filling increases the Pc of CNT(17, 0) by a factor of ∼25, and the Pc of CNT(10, 10) by a factor of ∼5. An inelastic CNT(17, 0) can be transformed into a superelastic CNT(17, 0) by filling C60 into CNTs. Moreover, C60@CNTs with larger diameters (21.76 A > d > 13.56 A) show the better radial elasticity compared with intrinsic CNTs. These characteristics can make C60@CNTs possess potential applications in pressure sensors, electromechanical oscillators, nanotube memory etc. In addition, C60@CNTs with larger diameters (21.76 A > d > 13.56 A) undergo two structure transitions under high pressure, which is well in agreement with the experimental results. The Lennard–Jones potential can describe the interaction between C60 and CNT well and explain radial collapse and recovery properties of C60@CNT completely, which can provide theoretical guidance for experimental results.

Self-powered photosensing characteristics of amorphous carbon/silicon heterostructures

Amorphous carbon (a-C) thin films are deposited on p-type silicon (Si) substrates using magnetron sputtering technique and the photodetector devices based on the a-C/Si heterostructures are fabricated. The photosensing characteristics of the devices are investigated. Under light irradiation, the fabricated a-C/Si device exhibits obvious photovoltaic characteristics. This enables its application as a self-powered photodetector operated at zero bias voltage. The obtained results show that the device is highly sensitive to broadband wavelength from the ultraviolet to near-infrared light, showing a high detectivity of ∼2.9 × 1013 cm Hz1/2 W−1, as well as a high responsitivity of ∼292.5 mA W−1, and a fast response speed of ∼8.3 μs. The mechanisms to the self-powered photosensing characteristics are clarified by the determination of the energy-band alignment near the interface of the a-C/Si heterostructures.

Highly Enhanced H 2 Sensing Performance of Few-Layer MoS 2 /SiO 2 /Si Heterojunctions by Surface Decoration of Pd Nanoparticles

A novel few-layer MoS2/SiO2/Si heterojunction is fabricated via DC magnetron sputtering technique, and Pd nanoparticles are further synthesized on the device surface. The results demonstrate that the fabricated sensor exhibits highly enhanced responses to H2 at room temperature due to the decoration of Pd nanoparticles. For example, the Pd-decorated MoS2/SiO2/Si heterojunction shows an excellent response of 9.2u2009×u2009103% to H2, which is much higher than the values for the Pd/SiO2/Si and MoS2/SiO2/Si heterojunctions. In addition, the H2 sensing properties of the fabricated heterojunction are dependent largely on the thickness of the Pd-nanoparticle layer and there is an optimized Pd thickness for the device to achieve the best sensing characteristics. Based on the microstructure characterization and electrical measurements, the sensing mechanisms of the Pd-decorated MoS2/SiO2/Si heterojunction are proposed. These results indicate that the Pd decoration of few-layer MoS2/SiO2/Si heterojunctions presents an effective strategy for the scalable fabrication of high-performance H2 sensors.

Enhanced photovoltaic characteristics of MoS2/Si hybrid solar cells by metal Pd chemical doping

MoS2/Si hybrid solar cells are fabricated and the device performances are improved via metal Pd chemical doping. Due to the incorporation of the Pd atoms in the MoS2 films, the photovoltaic characteristics of the solar cell are enhanced significantly and a 375% enhancement of the power conversion efficiency can be obtained.

Large Lateral Photovoltaic Effect in MoS2/GaAs Heterojunction

Molybdenum disulfide (MoS2) nanoscaled films are deposited on GaAs substrates via magnetron sputtering technique, and MoS2/GaAs heterojunctions are fabricated. The lateral photovoltaic effect (LPE) of the fabricated MoS2/GaAs heterojunctions is investigated. The results show that a large LPE can be obtained in the MoS2/n-GaAs heterojunction. The LPE exhibits a linear dependence on the position of the laser illumination and the considerably high sensitivity of 416.4xa0mVxa0mm−1. This sensitivity is much larger than the values in other reported MoS2-based devices. Comparatively, the LPE in the MoS2/p-GaAs heterojunction is much weaker. The mechanisms to the LPE are unveiled by constructing the energy-band alignment of the MoS2/GaAs heterojunctions. The excellent LPE characteristics make MoS2 films combined with GaAs semiconductors promising candidates for the application of high-performance position-sensitive detectors.

Correction: Enhanced photovoltaic characteristics of MoS2/Si hybrid solar cells by metal Pd chemical doping

Correction for ‘Enhanced photovoltaic characteristics of MoS2/Si hybrid solar cells by metal Pd chemical doping’ by L. Z. Hao et al., RSC Adv., 2016, 6, 1346–1350.