1. 云南师范大学可再生能源材料先进技术与制备教育部重点实验室, 太阳能研究所, 云南 昆明 650500 2. 四川文理学院物理与机电工程学院, 四川 达州 635000 3. Department of Physics and Astronomy, University of Toledo, Toledo，OH 43606, USA
Spectral Characteristics of Si Quantum Dots Embedded in SiNx Thin Films Prepared by Magnetron Co-Sputtering
CHEN Xiao-bo1, 2, YANG Wen1, DUAN Liang-fei1, ZHANG Li-yuan1, YANG Pei-zhi1*, SONG Zhao-ning3
1. Key Laboratory of Ministry of Education for Advance Technique and Preparation of Renewable Energy Materials, Institute of Solar Energy, Yunnan Normal University, Kunming 650500, China 2. School of Physics and Mech-Tronic Engineering, Sichuan University of Arts and Science, Dazhou 635000, China 3. Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606, USA
Abstract：The silicon-rich SiNx films were fabricated on Si(100) substrate and quartz substrate at different substrate temperatures varying from room temperature to 400 ℃ by bipolar pulse ane RF magnetron co-sputtering deposition technique. After deposition, the films were annealed in a nitrogen atmosphere by rapid photo-thermal annealing at 1 050 ℃ for 3 minutes. This thermal step allows the formation of the silicon quantum dots. Fourier transform infrared spectroscopy, Raman spectroscopy, grazing incidence X-ray diffraction and photoluminescence spectroscopy were used to analyze the bonding configurations, microstructures and luminescence properties of the films. The experimental results showed that: silicon-rich Si-N bonds were found in Fourier transform infrared spectra, suggesting that the silicon-rich SiNx films were successfully prepared; when the substrate temperature was not lower than 200 ℃, the Raman spectra of the films showed the transverse optical mode of Si-Si vibration, while the significant diffraction peaks of Si(111) and Si(311) were shown in grazing incidence X-ray diffraction spectra, confirming the formation of silicon quantum dots; our work indicated that there was an optimal substrate temperature (300 ℃), which could significantly increase the amount and the crystalline volume fraction of silicon quantum dots; three visible photoluminescence bands can be obtained for both 300 ℃ sample and 400 ℃ sample, and in combination with Raman results, the emission peaks were reasonably explained by using the quantum confinement effect and radiative recombination defect state of Si nanocrystals; the average size of the silicon quantum dots is 3.5 and 3.4 nm for the 300 ℃ sample and 400 ℃ sample, respectively. These results are useful for optimizing the fabrication parameters of silicon quantum dots embedded in SiNx thin films and have valuable implications for silicon based photoelectric device applications.
[1] Nguyen P D, Kepaptsoglou D M, Ramasse Q M, et al. Physical Review B, 2012, 85(8): 085315. [2] Huang R, Song J, Wang X, et al. Optics Letters, 2012, 37(4): 692. [3] Rodriguez-Gómez A, García-Valenzuela A, Haro-Poniatowski E, et al. Journal of Applied Physics, 2013, 113(23): 233102. [4] LIAO Wu-gang, ZENG Xiang-bin, WEN Guo-zhi, et al(廖武刚, 曾祥斌, 文国知, 等). Acta Physica Sinica(物理学报), 2013, 62(12): 126801. [5] Cen Z H, Chen T P, Liu Z, et al. Optics Express, 2010, 18(19): 20439. [6] Ha R, Kim S, Kim H J, et al. Journal of Nanoscience and Nanotechnology, 2012, 12(2): 1448. [7] Li P L, Gau C, Liu C W. Thin Solid Films, 2013, 529: 185. [8] Mavilla N R, Solanki C S, Vasi J. Physica E: Low-Dimensional Systems and Nanostructures, 2013, 52: 59. [9] Delachat F, Carrada M, Ferblantier G, et al. Nanotechnology, 2009, 20: 415608. [10] Jiang L, Zeng X, Zhang X. Journal of Non-Crystalline Solids, 2011, 357(10): 2187. [11] Wang M, Li D, Yuan Z, et al. Applied Physics Letter, 2007, 90(13): 131903. [12] Liao W, Zeng X, Wen X, et al. Journal of Electronic Materials, 2013, 42(12): 3445.
