CHEMICALLY DEPOSITED SILVER FILM USED AS A SERS-ACTIVE OVER-COATING LAYER FOR POLYMER FILM

When colloidal silver particles were chemically deposited onto polymer film as an over-coating layer, surface-enhanced Raman scattering (SERS) spectra could be collected for the surface analysis. SERS measurements of liquid crystal film were successfully performed without disturbing the surface morphology.

Performance improvement in polymeric thin film transistors using chemically modified both silver bottom contacts and dielectric surfaces

An efficient interface modification is introduced to improve the performance of polymeric thin film transistors. This efficient interface modification is first achieved by 4-fluorothiophenol（4-FTP） self-assembled monolayers（SAM） to chemically treat the silver source–drain（S/D） contacts while the silicon oxide（SiO2） dielectric interface is further primed by either hexamethyldisilazane（HMDS） or octyltrichlorosilane（OTS-C8）. Results show that contact resistance is the dominant factor that limits the field effect mobility of the PTDPPTFT4 transistors. With proper surface modification applied to both the dielectric surface and the bottom contacts, the field effect mobilities of the bottom-gate bottom-contact PTDPPTFT4 transistors were significantly improved from 0.15 cm^2·V^-1·s^-1 to 0.91 cm^2·V^-1·s^-1.

Preparation and microstructure characterization of a nano-sized Ti^(4+)-doped AgSnO_2 electrical contact material

A Ti^4＋-doped nano-structured AgSnO2 material was prepared using sol-gel method and characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, and scanning electron microscopy （SEM）. The results show that Ti^4＋ cations are successfully doped into the crystal lattice of SnO2, and thus significantly improve the electrical conductivity of the sample. Furthermore, the coating of Ag on Ti^4＋-doped SnO2 nano-sized particles enhances the surface wettability and enables the resulting AgSnO2 material to have better mechanical properties.

Enhanced efficiency of graphene-silicon Schottky junction solar cell through inverted pyramid arrays texturation

Nanostructures of silicon are gradually becoming hot candidate due to outstanding capability for trapping light and improving conversion efficiency of solar cell. In this paper, silicon nanowires（SiNWs） and silicon inverted pyramid arrays（SiIPs） were introduced on surface of Gr-Si solar cell through silver and copper-catalyzed chemical etching, respectively. The effects of SiNWs and SiIPs on carrier lifetime, optical properties and efficiency of Gr-SiNWs and Gr-SiIPs solar cells were systematically analyzed. The results show that the inverted pyramid arrays have more excellent ability for balancing antireflectance loss and surface area enlargement. The power conversion efficiency（PCE） and carrier lifetime of Gr-SiIPs devices respectively increase by 62% and 34% by comparing with that of Gr-SiNWs solar cells. Finally, the Gr-SiIPs cell with PCE of 5.63% was successfully achieved through nitric acid doping. This work proposes a new strategy to introduce the inverted pyramid arrays for improving the performance of Gr-Si solar cells.

Research on the surface passivation of nanostructure-textured crystalline silicon solar cell

Nanostructure-textured solar cell owns unique properties but has some shortages especially in its fabrication and passivation.In this paper,nanostructures for crystalline silicon solar cell have been synthesized by controllable method based on silver catalyzed chemical etching.In this way,only the front surface of cell is etched and rear surface is protected.It was found that cells textured via the new method obtained equally excellent optical while superior electrical properties compared with those textured via traditional HF/AgNO3 etching.The V OC and I SC of the cell were improved by 6% and 11%,respectively.Then the cells were passivated via a bi-layer passivation(SiO2 & SiN x),in contrast to traditional SiN x passivation.It was also found that cells with new passivation exhibited improved V OC and I SC by 4% and 25%,respectively.The encouraging results can provide fundamental data for developing the nanostructure-textured crystalline silicon solar cell in following researches.

Preparation and microwave absorption properties of flexible composites containing Ag decorated polystyrene powders

Polystyrene(PS)microspheres have the advantages of good stability,corrosion resistance and low density,which have a broad application prospect.In this paper,PS composite microspheres with 20%silver plating content were prepared by chemical plating method and incorporated into polydimethylsiloxane(PDMS)flexible matrix to prepare Ag@PS/PDMS flexible wave-absorbing materials.The electromagnetic parameters were adjusted to optimize the dielectric and wave-absorbing properties by varying the additional amount of Ag@PS composite microspheres in Ag@PS/PDMS composites.The X-ray diffraction(XRD)results proved the successful preparation of Ag@PS composite microspheres.The SEM and EDS images indicated that the Ag particles were attached to the external surface of PS.The presence of Ag particles in the Ag@PS composite microspheres enhances their electrical conductivity and enables the formation of a conductive network.This,in turn,improves the composites’dielectric constant.The optimal wave-absorbing capability of the composites was achieved when the Ag@PS composite microspheres were added at a weight percentage of 50%.When the sample attains a thickness of 1.8 mm,a reflection loss of at least-39.8 dB is attained at 10.4 GHz,along with a bandwidth of 1.6 GHz(9.1–10.7 GHz)for the effective absorption bandwidth(EAB).The pressure-sensitive properties of the pliable composites were investigated as well.The optimal pressure-sensitive performance of Ag@PS/PDMS composites was achieved with a 60 wt.% addition of Ag@PS composite microspheres.The resistance undergoes significant changes when subjected to pressure with a sensitivity of 9.7.The results indicate that the flexible composites’wave-absorption and pressuresensitivity properties can be modulated by adjusting the amount of Ag@PS composite microspheres added.