The atomic and electronic structures of Lithium-doped ZnO thin films studied by x-ray absorption and x-ray photoelectron spectroscopy

Autor: Cheng-Yuan Lu, 呂政遠
Rok vydání: 2016
Druh dokumentu: 學位論文 ; thesis
Popis: 104
In this work, the Li-doped ZnO (LZO) thin films were prepared by spin coating method and the percentage of Li-doping is of 0%, 3%, 5%, 10%, 20%, and 30%, respectively. We investigate how Li-doping percentage affects the electronic structure of ZnO thin films by x-ray absorption near-edge structure (XANES) and x-ray photoelectron spectroscopy (XPS). In addition to the 5%-LZO thin film, the O K- and Zn L3-edges XANES spectra of other LZO thin films reveal a decrease in the number of both O 2p and Zn 3d unoccupied states with an increase of Li-doping percentage. In other words, the Li dopant enhances the effect of O 2p-Zn 3d hybridization. However, in 5%-LZO thin film, the electron transfers from Zn to O atoms and suggesting that Li-doping increase the negative effective charge of O ions accompanying the increase of the number of O 2p-dangling bond. It is consistence with the analysis of XPS measuring results and implies that the number of O 2p-dangling bond is the main factor affecting the power conversion efficiency of the inverted solar cell structure of ITO/LZO-NPs/P3HT:ICBA/PEDOT:PSS/Au/Ag.
Databáze: Networked Digital Library of Theses & Dissertations