半导体型单壁碳纳米管中激子的一维扩散模型

A Study on the One-dimensional Diffusion Model of Excitons in Semiconducting Single-walled Carbon Nanotubes

针对架桥生长的半导体型单壁碳纳米管中激子的扩散特性,建立激子的一维扩散模型,进而考察研究碳纳米管中激子的扩散及复合发光过程.通过求解激子的一维扩散方程,模拟在有限长度下的碳管中激子密度、发光强度随管长和激子扩散长度之间的变化关系.研究结果表明,激子的扩散长度对激子发光强度有着重要影响,较大的激子扩散长度容易导致激子的边界淬灭,降低发光强度和发光效率.研究结果不但有助于碳纳米管中激子的扩散长度的测量,而且有助于未来对基于碳管的单激子器件尺寸的设计研究.

This paper described the one - dimensional diffusion channel of excitons within semicon- ducting carbon nanotubes. The diffusion equation for the excitons was built on the basis of the process of the generation, diffusion and recombination of the excitons. By solving the equation under the proper boundary conditions, the exciton density and the photoluminescence intensity as a function of the carbon nanotubes length and exciton diffusion length were obtained. The results show that the diffusion length of exciton has important effect on the emission intensity of the exciton, and the large exciton diffusion length can easily lead to the quenching of the boundary of the exciton, and reduce the luminescence in- tensity and luminous efficiency. These results provide the approaches for investigating exciton diffusion length in one dimensional material as well as for the design of single exciton device size in the future.