Xinshuai Zhang

Fabrication and antireflection properties of solar cells with pyramid-nanohole texture by caesium chloride lithography

Pyramids and nanoholes are integrated together to form a micro-nano-texture on silicon surface in order to suppress reflection for silicon solar cell application. The nanoholes are formed by inductively coupled plasma (ICP) dry etching employing a nanoporous aluminum (Al) mask which is fabricated by caesium chloride (CsCl) nanoislands lift-off technique. Reflection of less than 4% can be reached by pyramid-nanohole texture, which is much lower than that from pure pyramids or nanoholes texture. Higher short circuit current density (J(sc)) and photovoltaic conversion efficiency (PCE) are obtained for the solar cell with pyramid-nanohole texture due to its better antireflection. The average diameter and depth of the nanoholes affect the solar cell properties. The smaller and deeper nanoholes can suppress reflection a lot, but meanwhile, the formation of them means more crystal lattice defects generated from ICP etching. An optimized diameter of 800 nm and depth of 1 mu m for the nanoholes are obtained in our experiments to get the best photovoltaic performance that is a PCE of 14.89% with a J(sc) of 38.25 mA cm(-2) and an open circuit voltage (V-oc) of 544.8 mV.

Fabrication of silicon nanotip arrays with high aspect ratio by cesium chloride self-assembly and dry etching

Nanotip arrays with high aspect ratio, which have attracted much attention due to their potential applications, have been fabricated by many methods. Dry etching combined with self-assembly masks is widely used because of the convenience of dry etching and high throughput of self-assembly. In this paper, we report a method combining Cesium Chloride (CsCl) self-assembly with inductively coupled plasma (ICP) dry etching to fabricate silicon nanotip arrays with high aspect ratio and silicon nanotip arrays with aspect ratio 15 have been achieved after optimization of all parameters.

Large rotating magnetocaloric effect in ErAlO3 single crystal

Magnetic and magnetocaloric properties of ErAlO3 single crystal were investigated. Magnetization of ErAlO3 shows obvious anisotropy when magnetic field is applied along the a, b and c axes, which leads to large anisotropic magnetic entropy change. In particular, large rotating field entropy change from the b to c axis within the bc plane is obtained and reaches 9.7 J/kg K at 14 K in a field of 5 T. This suggests the possibility of using ErAlO3 single crystal for magnetic refrigerators by rotating its magnetization vector rather than moving it in and out of the magnet.Magnetic and magnetocaloric properties of ErAlO3 single crystal were investigated. Magnetization of ErAlO3 shows obvious anisotropy when magnetic field is applied along the a, b and c axes, which leads to large anisotropic magnetic entropy change. In particular, large rotating field entropy change from the b to c axis within the bc plane is obtained and reaches 9.7 J/kg K at 14 K in a field of 5 T. This suggests the possibility of using ErAlO3 single crystal for magnetic refrigerators by rotating its magnetization vector rather than moving it in and out of the magnet.