Estimation of band gap energy of Mg x Zn 1‐ x O films by photocurrent

Autor: K. Aota, Michiko Nakagawa, Hiroshi Osada, T. Ojima, Yasube Kashiwaba, Shigeki Chiba, Y. Kashiwaba, Masahiro Daibo, Tetsuya Chiba, Takami Abe, Akira Nakagawa, Ikuo Niikura, Shuzo Takahashi
Rok vydání: 2014
Předmět:
Zdroj: physica status solidi c. 11:1345-1348
ISSN: 1610-1642
1862-6351
Popis: The band gap energy (Eg) of high-quality Mgx Zn1-xO films grown on ZnO (0001) substrates by the plasma-assisted reactive evaporation method using a ZnMg alloy could be estimated by the photocurrent (Iph). Measurement of Iph was more useful than photoluminescence (PL), transmittance or reflectance (R) spectra measurements for determination of Eg of materials with large binding energy of the excitons. The values estimated from the relation of (αkhν)2–hv plots using optical absorption coefficient αk calculated from extinction coefficient k were close to the peak energy of PL or R of these films. The values estimated from the relation of (αphhv)2–hν plots using inter-band absorption coefficient αph calculated from Iph spectra were larger than the values of peak energy of PL or R despite strong absorption of the excitons. Therefore, it was thought that these values are closer to Eg. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Databáze: OpenAIRE
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