以X光吸收光譜探討Cu2Se相關材料之電子與原子結構

Electronic and structural properties of Cu2Se related materials studied by X-ray absorption spectroscopy

游家源(Jia-Yuan You)

指導教授 ： 張經霖

淡江大學/理學院/物理學系碩士班/碩士(2015年)

https://doi.org/10.6846/TKU.2015.01078

摘要

本文主要為針對半導體熱電材料Cu2Se以及其相關材料分別為：降低Cu濃度以及摻雜Ni之X光吸收近邊緣結構(X-ray Absorption Near Edge Structure，XANES)和延伸X光吸收精細結構(Extended X-ray Absorption Fine Structure，EXAFS)數據分析。結果指出降低Cu濃度後Cu價數及主要載子電洞隨之增加，進而增加其導電性；而反螢石結構之非常態Cu的分佈改變降低其聲子熱導。摻雜Ni後原本不參與電子轉移的Se將參與電子轉移，電子由Cu轉移至Ni，而其反螢石結構晶格之靜態亂序增加將降低其聲子熱導。

關鍵字

Cu2Se ； XANES ； EXAFS ； 熱電材料

並列摘要

This article is mainly for the semiconductor and related materials thermoelectric materials Cu2Se. We compare the sample concentration changes and doping with the absorption spectroscopy of X-ray Absorption Near Edge Structure and Extended X-ray Absorption Fine Structure. The results indicate that after we reduce the concentration of Cu, its main hole-carriers and Cu valence increases, thereby increasing its electrical conductivity. The change in the distribution of antifluorite structure of Cu reduce its phonon thermal conductivity as we reduce the concentration of Cu. Se is not involved in electron transfer, but doped Ni, Se will participate in electron transfer, electron transfer from Cu to Ni, and its antifluorite structure of the static lattice disorder increase will reduce the phonon thermal conductivity.

並列關鍵字

Cu2Se ； XANES ； EXAFS ； thermoelectric material

參考文獻

Abhandlungen der Deutschen Akademie Wissenschaften zu Berlin,

53, 3286-3289, (1984)

[3] Tatsuya Okada et al., Journal of Non-Crystalline Solids, 250-252,

[4] X-Ray Absorption : Principles, Application, Techniques of EXAFS, SEXAFS, SEXAFS and XANES” , edited by D. C. Koningsberger, and R. Prins, Chem. Analysis Vol. 92 (Wiley 1988).

[9] Synchrotron Radiation Research”, edited by H. Winick, S. Doniach (1980).