Even though economic advantages of silicon still keep it as the dominant material for the solar cell industry in the near future, crystal silicon in the diamond structure (d-Si) is an indirect bandgap semiconductor which prevents to consider it as a next-generation platform for optical material technologies. Here, we report the formation of a new allotrope of silicon on surface, Si-9, using a novel two-step synthesis methodology. First, a film of amorphous silicon was produced by using pulsed laser deposition method, and second, new Si-9 was synthesized under irradiation of coherent electron beam on the amorphous Si film. It is important that the structure of Si9, forming six-membered sp3 silicon rings and involving 9 silicon atoms in one unit, possesses a direct bandgap near 1.59 eV, around which we have measured the emission peak in photoluminescence spectra on the pure Si-9. It is discovered that Si-9 can be easily doped as both p- and n-type on surface, where boron and nitrogen are demonstrated as the most promising elements for the p-type and n-type doping in Si-9, respectively, due to their low formation energies and reductions in the band gap. These properties suggest great potential in constructing a novel Si-9-based p-n junction which is highly desired for future industrial application of optoelectronic technologies and photovoltaic devices. Publication name | MATERIALS RESEARCH EXPRESS, 6 (10):10.1088/2053-1591/ab390e OCT 2019 | Author(s) | Huang, Wei-Qi; Huang, Zhong-Mei; Liu, Shi-Rong; Peng, Hong-Yan | Corresponding author(s) | HUANG Weiqi wqhuang@gzu.edu.cn Hainan Normal Univ, Dept Phys, Haikou 571158, Hainan, Peoples R China. | Author(s) from IGCAS | LIU Shirong | View here for the details
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