New Insights on the Burstein-Moss Shift and Band Gap Narrowing in Indium-Doped Zinc Oxide Thin Films.

Autor: Saw KG; Physics Programme, School of Distance Education, Universiti Sains Malaysia, 11800, Penang, Malaysia; Institute of Nano-optoelectronics Research and Technology, Sains@USM, 11900, Penang, Malaysia., Aznan NM; Physics Programme, School of Distance Education, Universiti Sains Malaysia, 11800, Penang, Malaysia., Yam FK; School of Physics, Universiti Sains Malaysia, 11800, Penang, Malaysia., Ng SS; Institute of Nano-optoelectronics Research and Technology, Sains@USM, 11900, Penang, Malaysia., Pung SY; School of Materials and Mineral Resources Eng., Universiti Sains Malaysia, 14300, Nibong, Tebal, Malaysia.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2015 Oct 30; Vol. 10 (10), pp. e0141180. Date of Electronic Publication: 2015 Oct 30 (Print Publication: 2015).
DOI: 10.1371/journal.pone.0141180
Abstrakt: The Burstein-Moss shift and band gap narrowing of sputtered indium-doped zinc oxide (IZO) thin films are investigated as a function of carrier concentrations. The optical band gap shifts below the carrier concentration of 5.61 × 1019 cm-3 are well-described by the Burstein-Moss model. For carrier concentrations higher than 8.71 × 1019 cm-3 the shift decreases, indicating that band gap narrowing mechanisms are increasingly significant and are competing with the Burstein-Moss effect. The incorporation of In causes the resistivity to decrease three orders of magnitude. As the mean-free path of carriers is less than the crystallite size, the resistivity is probably affected by ionized impurities as well as defect scattering mechanisms, but not grain boundary scattering. The c lattice constant as well as film stress is observed to increase in stages with increasing carrier concentration. The asymmetric XPS Zn 2p3/2 peak in the film with the highest carrier concentration of 7.02 × 1020 cm-3 suggests the presence of stacking defects in the ZnO lattice. The Raman peak at 274 cm-1 is attributed to lattice defects introduced by In dopants.
Databáze: MEDLINE
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