TY - JOUR
T1 - Photoelectron spectroscopy and optical properties of al-doped zno films prepared by sputtering with radio frequency power applied to al target
AU - Tseng, Chun An
AU - Lin, Jing Chie
AU - Weng, Wei Heng
AU - Lin, Chen Chun
PY - 2013/2
Y1 - 2013/2
N2 - Al-doped ZnO (AZO) films were prepared on a glass substrate using a magnetron sputtering system. The metallic aluminum and ZnO targets were bombarded by radio frequency power source. The Al-dopant concentration of the films, analyzed by energy-dispersive spectroscopy, increased with increasing RF power. The electrical resistivity of the films, measured by four-point probe, revealed a decrease from 3:43 × 10-2 to 3:29 × 10 -3 ωcm with increasing Al-content from 0.85 to 4.34 at. %. The crystal structure analyzed by grazing incidence X-ray diffraction indicated that all of the films prepared by sputtering with RF power preferred a stronger texture on (002) orientation than those with DC power applied to Al target. The optical transmittance, measured by UV-visible, indicated an average transmittance higher than 82% for all the films in visible region, and increased with Al-content; however, it reversed at 4.34 at. %. The band gap of the films increased from 3.39 to 3.58 eV with increasing RF power. Ultraviolet photoelectron spectroscopy (UPS) analysis revealed that a characteristic peak at approximately 5-7 eV was found in the AZO films due to the O 2p valence electrons. Meanwhile, the work functions of the undoped ZnO film and various AZO films were measured by UPS decreased from 4.9 to 4.5 eV with increasing Al-content. The chemical composition of the films was analyzed by X-ray photoelectron spectroscopy with Gaussian-resolved fitting. According to XPS analysis of O 1s for the films, we inferred that the decrease in electrical resistivity of the film with increasing Al-dopant concentration was predominated by the concentration of oxygen vacancies.
AB - Al-doped ZnO (AZO) films were prepared on a glass substrate using a magnetron sputtering system. The metallic aluminum and ZnO targets were bombarded by radio frequency power source. The Al-dopant concentration of the films, analyzed by energy-dispersive spectroscopy, increased with increasing RF power. The electrical resistivity of the films, measured by four-point probe, revealed a decrease from 3:43 × 10-2 to 3:29 × 10 -3 ωcm with increasing Al-content from 0.85 to 4.34 at. %. The crystal structure analyzed by grazing incidence X-ray diffraction indicated that all of the films prepared by sputtering with RF power preferred a stronger texture on (002) orientation than those with DC power applied to Al target. The optical transmittance, measured by UV-visible, indicated an average transmittance higher than 82% for all the films in visible region, and increased with Al-content; however, it reversed at 4.34 at. %. The band gap of the films increased from 3.39 to 3.58 eV with increasing RF power. Ultraviolet photoelectron spectroscopy (UPS) analysis revealed that a characteristic peak at approximately 5-7 eV was found in the AZO films due to the O 2p valence electrons. Meanwhile, the work functions of the undoped ZnO film and various AZO films were measured by UPS decreased from 4.9 to 4.5 eV with increasing Al-content. The chemical composition of the films was analyzed by X-ray photoelectron spectroscopy with Gaussian-resolved fitting. According to XPS analysis of O 1s for the films, we inferred that the decrease in electrical resistivity of the film with increasing Al-dopant concentration was predominated by the concentration of oxygen vacancies.
UR - http://www.scopus.com/inward/record.url?scp=84874137888&partnerID=8YFLogxK
U2 - 10.7567/JJAP.52.025801
DO - 10.7567/JJAP.52.025801
M3 - 期刊論文
AN - SCOPUS:84874137888
SN - 0021-4922
VL - 52
JO - Japanese Journal of Applied Physics
JF - Japanese Journal of Applied Physics
IS - 2
M1 - 025801
ER -