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An n-type Si nanowire (SiNW) solar cell based on transition metal oxides V2O5 and TiO2 has been fabricated. The cell is demonstrated in the ITO/V2O5/n-SiNWs/TiO2/Al heterojunction structure, in which the V2O5 and TiO2 work as the hole- and the electron-selective layers, respectively. Parameters of cells with different lengths of nanowires have been investigated. Owing to the excellent light trapping effect of nanowire arrays and superior carrier transporting properties of thin V2O5 and TiO2 layers, an improved power conversion efficiency of 12.7% has been achieved in a cell with 1.45-μm-long nanowires. Due to the large work function difference between V2O5 and n-Si, a build-in potential of 0.75 V was obtained from the capacitance-voltage measurement, which implies the possibility of achieving a large open circuit voltage for these nanowire solar cells. The efficiency loss is mainly caused by the recombination via the defects on the unpassivated surface of SiNWs. By solving this problem, the cell efficiency may be improved further and realize the application in PV industries.

One-step sputtering with elevated substrate temperature was used to fabricate Cu(In,Ga)Se2 (CIGSe) and Cu(In,Ga)S2 (CIGS) films. We investigated the influence of this approach on the structure and electrical properties of CIGSe and CIGS films. Compact films with large grain size were achieved at relatively low substrate temperatures below 400 °C without post-treatments. The films obtained from CIGSe targets showed larger grain and higher crystallinity compared to that prepared from CIGS targets. It was found that the substrate temperature over 400 °C brought some undesirable effects on the film quality, such as voids and secondary phases. The loss of Ga and In during the fabrication process was detected, resulting in the formation of Cu-rich films with low carrier density. HBr solution etching reduced the Cu/(In + Ga) ratio of the sputtered films, leading to the improvement of the performance of the CIGSe solar cells along with the enhancement of carrier density.

Copper oxide nanowires and nanoparticles were fabricated through electrospinning followed by calcinations in different heating conditions. It was found that the solution viscosity and environment humidity had great impact on the morphologies of precursor nanowires, and the parameters of heat treatment, including final temperature and heating rate, significantly affected the product morphologies.

We fabricate nano-columnar tungsten (W) films on polycrystalline silicon substrates by magnetron sputtering using a grazing angle deposition technique. The deposition process is performed at a base pressure of 5×10−4 Pa. The intersection angle between the direction of the incident beam and the normal direction of the substrate is set as 85°. Separate as well as synergetic irradiations of 30/50 keV deuterium ions and 60 keV helium ions are carried out for the nano-columnar W. Samples of normal structure W are also irradiated under the same conditions as a comparison. Scanning electron microscopy and x-ray diffraction are used to characterize the structure of the as-prepared as well as the irradiated samples. The experimental results show that blisters are difficult to form on the surface of nano-columnar W under the irradiation conditions in this work, which could be due to the particular structure.