Silicon-nanowire (Si-NW) array, prepared by an electroless chemical-etching method, shows excellent optical antireflection property over a wide spectral bandwidth. The influence of the wire length on the optical antireflection property and the solar cell performance were studied for both the Si-NW array solar cells and the planar solar cells. The reflectance of NWs solar cells is almost invariable and much lower than that of the planar solar cells but the performance of planar solar cells is the best. Results show the performance of NWs solar cells is strongly affected by some other factors such as surface passivation and electrode-contact property.

We have demonstrated an organic light-emitting diode based on molybdenum oxide $\left(\mathrm{Mo}{\mathrm{O}}_x\right)$ doped $4,4^{\prime },4^{″}$ -tris(3-methylphenylphenylamino)triphenylamine $\left(m\text{-}\mathrm{MTDATA}\right)$ as a $p$ -type doping hole injection layer. The tris-(8-hydroxyquinoline) aluminum $\left(\mathrm{Al}{q}_3\right)$ -based organic light-emitting diodes show high brightness at very low operating voltage, $100\mathrm{cd}∕{\mathrm{m}}^2$ at $3.2\mathrm{V}$ and $1000\mathrm{cd}∕{\mathrm{m}}^2$ at $4.4\mathrm{V}$ , corresponding to a low turn-on voltage of $2.4\mathrm{V}$ . Such improved properties are attributed to the formation of the charge transfer complex produced by doping $\mathrm{Mo}{\mathrm{O}}_x$ into $m\text{-}\mathrm{MTDATA}$ , which provides much more free hole carriers, and the introduction of an efficient electron-injecting layer to improve the performance.

High performance radial p-n junction solar cells based on silicon nanopillar array were synthesized from p-type silicon substrates and compared with planar cell. These radial p-n junction cells exhibited considerable higher short-circuit current, due to their unique carriers' decoupling mechanism. After the electrode enhancement via light induced plating, a best efficiency of near 12% was achieved for radial p-n junction solar cell, which is better than the planar control cell.

In this study, we investigated an absorber based on a center-aligned tandem nanopillar array for ultra-broadband solar energy harvesting theoretically. A high-efficiency, omnidirectional absorber was obtained by introducing the center-aligned tandem nanopillar array embedded in an Al₂O₃ dielectric layer. The multi-coupling modes at different wavelengths were interpreted. The strong absorption can be adjusted by changing the radii and heights of nanopillars. According to the simulation results, the average absorptance of the absorber exceeded 94% in the wavelength range from 300 nm to 2000 nm. In addition, the high-efficiency absorption was insensitive to the incident angle and polarization state. The research not only proposed an absorber which possesses a huge potential value for application areas, such as thermal photovoltaic systems, infrared detection, and isotropic absorption sensors, but also pointed out a new way to design an absorber with high efficiency in an ultrabroad wavelength range.