Size-dependent optical absorption of silicon nanocrystals embedded in SiO₂/Si₃N₄ hybrid matrix

详细信息    查看全文

• 作者：X. Jia ; ^{darcyjia@gmail.com} ; D. Di ; H. Xia ; L. Wu ; Z. Lin ; G. Conibeer
• 关键词：Optical characterization ; Quantum dots ; Silicon nitrides ; Solar cells
• 刊名：Journal of Non-Crystalline Solids
• 出版年：2013
• 出版时间：15 February, 2013
• 年：2013
• 卷：362
• 期：Complete
• 页码：169-174
• 全文大小：689 K

文摘

Optical constants of silicon quantum dots (Si QDs) in SiO₂/Si₃N₄ hybrid matrix on quartz substrates have been determined in the wavelength range of 350-2500 nm. Forouhi-Bloomer (F-B) dispersion model is applied to describe the optical properties of silicon nanocrystals and the mismatch due to global fitting is fixed point by point. To extract the specific optical bandgap of silicon nanocrystal samples, Tauc-plots with ¦Ã = 1/2 and ¦Ã = 1/3 are used and discussed for the spectral range of 2 eV-3 eV. The effect of quantum dot size on the optical bandgap is explored. The results from both Tauc-plot and photoluminescence show the trend that the optical bandgap increases with decreasing quantum dot size, which agrees with the prediction of quantum confinement.