Applied Technology

New Materials Invented for Solar Cells

Researchers in the Institute of Microelectronics (IME) of CAS recently made a major breakthrough in the research of multicrystal black silicon solar cells. Black silicon is a kind of silicon material with low reflection, comparing with conventional silicon material, black silicon exhibits strong light absorption capability and can be used in solar cells industry. Research Prof. Xia Yang and his team from the Key Laboratory of Microelectronics Devices & Integrated Technology of the Institute firstly proposed to produce black silicon by using plasma immersion ion implantation (PIII) technology. The black silicon with multi-kinds of microstructure has been achieved by using self-made PIII system. The average reflection of the black silicon is 0.5% in visible wavelength region, which can compare with the black silicon achieved by irradiating fem to second laser pulses. Meanwhile, PIII, as a low cost and high efficiency process, is more proposed for mass production. By optimizing the textured structure and follow-up process, researchers obtained 17.46% average efficiency solar cells based on PIII textured 156mm×156mm multicrystal silicon, and the highest efficiency of solar cells is up to 17.65% in this patch. The relevant results have been published on Solar Energy, Energy Procedia, Journal of Electron Spectroscopy and Related Phenomena, Acta Physica Sinica, etc. The project team has also applied for more than 30 patents in this field.

Series Progress Obtained in Nano-carbon Materials

A research group, led by Prof. Yan Xingbin at the State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics has carried out a series of studies on the nano-carbon material used as the electrode materials in super-capacitors since 2009. They have developed novel nano-carbon materials with environmental friendly, wide operating temperature, high energy density and power density, and achieved good results. Recently, the group investigated the electrochemical behavior of graphene sheet (GNSs) in ionic liquids using the electrochemical technique, especially the effects of molar concentration of ionic liquids, temperature, organic solvent and the alkyl chain length of alkylimidazolium tetra?uoroborate ionic liquid on the super-capacitive performance of GNSs. The results published recently in J. Mater. Chem. (2011, 21, 13205; 2012, 22, 8853). In addition, the group has prepared respectively the graphene film and the shape memory electrode material via the self-assembly and composite technology. These materials have shown excellent capacitance performance, the result of which was published in Electrochim Acta. 2012, 60, 41 and J. Power. Sources. 2012, 213, 350, respectively. Besides, the group has also investigated the supercapacitive performances of carbon nanotubes, mesoporous carbon and carbon nanofiber materials, especially the effects of the doping content, surface functional groups as well as heat treatment temperature on the capacitor performance of GNSs. These results were published in J. Power Sources. (2011, 196, 10472; 2011, 196, 7841; 2012, 204, 220; 2012, 199, 373) and J. Electrochem. Society. 2012, 159, A1.

New Approach to Produce Hydrogen

A highly efficient process for the decomposition of hydrous hydrazine to produce hydrogen under ambient temperature over a low cost nickel catalyst was realized for the first time by a research team headed by Prof. Zhang Tao at the Dalian Institute of Chemical Physics, CAS. Prof. Zhang Tao and his team have been engaged in the R&D of hydrazine decomposition catalysts for a long time, and basic studies on highly efficient utilization of noble metals as well as substitution of noble metals with non-noble metals have been keenly persuaded. In this new catalyst system, they succeeded in preparing a new type of Ni/Al2O3 catalyst by using hydrotalcite as the precursor. The new catalyst possessed properties of high metal dispersion and basicity, which could decompose hydrazine completely under ambient temperature, with a hydrogen selectivity as high as 98%. This investigation rendered for the first time a process for highly efficient decomposition of hydrous hydrazine to produce hydrogen over a non-noble metal catalyst under ambient temperature, and opened a new route for hydrogen production. The results were published in the journal of Angew. Chem. Int. Ed. in the form of communication.