Light trapping in randomly arranged silicon nanorocket arrays for photovoltaic applications.

Realization of broadband optical absorption enhancement in thin film c-Si solar cells is essential for improving energy conversion efficiency and reducing cost. Here, we demonstrate the fabrication of randomly arranged silicon nanorocket (SiNR) arrays as a new light trapping structure design for thin film silicon solar cells. The optical absorption of the randomly arranged SiNR arrays is investigated via finite-difference-frequency-domain (FDTD) simulation. Our calculations reveal that the light trapping structures facilitate the coupling of incident sunlight into the resonant modes and lead to significant photon absorption enhancement across a wide solar spectrum, resulting in ultimate efficiencies superior to nanowire and nanohole arrays with the same thickness. Our findings indicate that the randomly arranged SiNR arrays fabricated by the simple self-assembly and etching approach can have a significant impact on performance improvement in thin film silicon solar cells.

Metal-catalyzed electroless etching of silicon in aerated HF/H2O vapor for facile fabrication of silicon nanostructures.

Inspired by metal corrosion in air, we demonstrate that metal-catalyzed electroless etching (MCEE) of silicon can be performed simply in aerated HF/H2O vapor for facile fabrication of three-dimensional silicon nanostructures such as silicon nanowires (SiNW) arrays. Compared to MCEE commonly performed in aqueous HF solution, the present pseudo gas phase etching offers exceptional simplicity, flexibility, environmental friendliness, and scalability for the fabrication of three-dimensional silicon nanostructures with considerable depths because of replacement of harsh oxidants such as H2O2 and AgNO3 by environmental-green and ubiquitous oxygen in air, minimum water consumption, and full utilization of HF.

Gold-Sensitized Silicon/ZnO Core/Shell Nanowire Array for Solar Water Splitting.

Solar water splitting represents one of the most promising strategies in the quest for clean and renewable energy. However, low conversion efficiency, use of sacrificial agents, and external bias for current water splitting system limit its practical application. Here, a gold-sensitized Si/ZnOcore/shell nanowire photoelectrochemical (PEC) cell is reported for efficient solar water oxidation. We demonstrated gold-sensitized n-Si/n-ZnO nanowire arrays exhibited higher energy conversion efficiency than gold-sensitized p-Si/n-ZnO nanowire arrays due to the favorable energy-band alignment characteristics. Without any assistance from an external electrical source and sacrificial reagents, gold-sensitized n-Si/n-ZnO core/shell nanowire array photoanode achieved unbiased water splitting under simulated solar light illumination. This method opens a promising venue to cost-efficient production of solar fuels.

[Removal of the displaced implant from the maxillary sinus: report of one case].

Accidental displacement of end osseous implants into the maxillary sinus is an uncommon but potential complication in implant surgery due to the special features of the posterior aspect of the maxillary bone. The authors reported one case implant displacement into the maxillary sinus by lateral window technique. The causes for displacement, preventive measures were summarized, in order to avoid this kind of complication.