Silver nanoparticles(AgNPs) with well-distributed sizes were prepared by magnetron sputtering on slides and crystalline silicon(c-Si) solar cell following by annealing at different temperatures. The morphologies,optical and photovoltaic performance were investigated in detail. The spectroscopic result shows that two resonance peaks resulting from coupling effect among neighboring particles are difficult to obtain by other chemical methods.The photovoltaic performances reveal that the solar cells decorated with AgNPs significantly are degraded, including a maximal decrease of 20.4 % in short-circuit density and 53.9 % in energy conversion efficiency. The lowest efficiency achieved is 5.85 % for c-Si solar cells with AgNPs annealed at 500 ℃. The deterioration should result from the synergetic effect of the intrinsic absorption of single particle and coupling absorption between neighboring particles.
GeS6 chalcogenide amorphous fi lm was deposited on glass substrate via PLD(pulsed laser deposition) technique. The performance and structure of the fi lm was characterized by XRD(X-ray diffraction), SEM(Scanning Electron Microscopy), EDS(Energy Dispersive Spectroscopy), optical transmission spectra, and Raman spectra, etc. The GeS6 amorphous fi lm was irradiated by 532 nm linearly polarized light, and its photoinduced darkening was investigated. The results showed that the GeS6 chalcogenide amorphous fi lm was smooth and compact with uniform thickness and combined with the substrate fi rmly, and its chemical composition was in consistency with the bulky target. When laser energy was fi xed, the transparence of the fi lm declined with the increase of the laser irradiation time. Obvious photo-induced darkening and relaxation phenomenon of the fi lm after laser irradiation were observed in this investigation.
Using the oxidation method from vanadium metal thin films by magnetron sputtering, under the fixed annealing parameters of temperature(400 ℃) and oxygen pressure(103 Pa), we fabricated a series of vanadium dioxide thin films through the change of annealing durations or substrates(quartz glass or AZOcovered glass). Characterization of the thermochromic properties together with the X-ray diffraction(XRD) and field emission scanning electron microscopy(FE-SEM) indicates that appropriate annealing duration is a key factor to obtain pure VO2 films and AZO-covered glass is more suitable to obtain the VO2 films with high visible transmittance, good crystallinity and larger near-infrared switching efficiencies(maximum 34% at 2000 nm) compared with the substrate of quartz glass. However, VO2 films on quartz glass exhibit narrower loop(7 ℃) with smart reversible response to temperature. Depth profile XPS spectra further indicate that for the films fabricated on quartz glass from thicker V metal films, the existence of low valence vanadium oxides is inevitable and leads to a lower transmittance in the region of visible light.
A TiO2/P3HT hybrid solar cell was fabricated by infiltrating P3HT into the pores of TiO2 nanorod arrays. To further enhance the photovoltaic performance, anthracene-9-carboxylic acid was employed to modify the interface of TiO2/P3HT before P3HT was coated. Results revealed that the interface treatment significantly enhances the photovoltaic performance of the cell. The efficiency of the hybrid solar cells reaches 0.28% after interface modification, which is three times higher compared with the un-modified one. We find that except for the increased exciton dissociation efficiency recognized by the previous reports, the suppressing of electron back recombination is another important factor leading to the enhanced photovoltaic performance.
We studied the local structure and properties of six-fold coordinated silicon(Si[6]) in BaOSiO2-P2O5 glasses. Nuclear magnetic resonance(NMR) and Raman spectroscopy revealed the existence of sixfold coordinated silicon species and network former units(NFUs) in the BaO-SiO2-P2O5 glasses. The glass transition temperature(Tg), which was measured by differential scanning calorimetry, increased rapidly along with the increase of SiO2 from 0 to 10 mol%, then declined and finally increased again, which showed a "Z" trend along with the increase of SiO2 while the density of the glasses showed the opposite trend. When the addition of SiO2 is 16 mol%, Tg decreased to an extremely low value(807.9 K). Besides, the Vickers indentation hardness(Hv) had been significantly enhanced from 4.66 to 6.63 GPa by adding 16 mol% SiO2. Furthermore, the liquid fragility index(m) of the glasses declined slowly firstly and then increased rapidly when the amount of SiO2 is greater than 13 mol%.
The effect of ZrO2 content on the performance of vitrified bond was discussed. The results showed that when the ZrO2 content was less than 2 mol%, Zr4+ could enter into the glassy network as mending nets and agglomeration composition. In this case, with the increasing of ZrO2, the vitrified bond's bending strength increased and the expansion coefficient decreased. It was also found that the wetting angle between the vitrified bond and diamond got small because Zr4+ was enriched on diamond surface. When ZrO2 content was more than 2 mol%, a part of ZrO2 existing in vitrified bond as ZrO2 particles played the role in nucleating agents and promoting the separation of spodttrnene. When ZrO2 content was 3 mol%, the bending strength of the vitrified bond reached its maximum of 128 MPa and the wetting angle with the diamond reached its minimum of 37.6°.