First-principles studies of the vibrational properties of amorphous carbon nitrides

• Published in: Chinese physics B 2013, Vol.22 (1), p.467-471
• Main Author: 牛丽 王选章 朱嘉琦 高巍
• Format: Article
• Language: English
• Subjects: Amorphous materials; Carbon; Carbon nitride; Density; Electric fields; Mathematical analysis; Mathematical models; Raman spectra; Vibration; 分子动力学; 拉曼光谱; 振动特性; 无定形碳; 氮化物; 氮化碳薄膜; 第一原理; 计算结果
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/22/1/017101

Raman spectra of amorphous carbon nitride films （a-C：N） resemble those of typical amorphous carbon （a-C）, and no specific features in the spectra are shown due to N doping. The present work provides a correlation between the microstructure and vibrational properties of a-C：N films from first principles. The six periodic model structures of 64 atoms with various mass densities and nitrogen contents are generated by the liquid-quench method using Car-Parinello molecular dynamics. By using Raman coupling tensors calculated with the finite electric field method, Raman spectra are obtained. The calculated results show that the vibrations of C=N could directly contribute to the Raman spectrum. The similarity of the Raman line shapes of N-doped and N-free amorphous carbons is due to the overlapping of C=N and C=C vibration bands. In addition, the origin of characteristic Raman peaks is also given.