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Full-Text Articles in Physics
Stable Highly Conductive Zno Via Reduction Of Zn Vacancies, David C. Look, Timothy C. Droubay, Scott A. Chambers
Stable Highly Conductive Zno Via Reduction Of Zn Vacancies, David C. Look, Timothy C. Droubay, Scott A. Chambers
Physics Faculty Publications
Growth of Ga-doped ZnO by pulsed laser deposition at 200 °C in an ambient of Ar and H2produces a resistivity of 1.5 × 10−4 Ω-cm, stable to 500 °C. The resistivity can be further reduced to 1.2 × 10−4 Ω-cm by annealing on Zn foil, which reduces the compensating Zn-vacancy acceptor concentration NA to 5 × 1019 cm−3, only 3% of the Ga-donor concentration ND of 1.6 × 1021 cm−3, with ND and NA determined from a degenerate mobility theory. The plasmon-resonance wavelength is only 1060 …
Highly Conductive Zno Grown By Pulsed Laser Deposition In Pure Ar, Robin C. Scott, Kevin D. Leedy, Burhan Bayraktaroglu, David C. Look, Yong-Hang Zhang
Highly Conductive Zno Grown By Pulsed Laser Deposition In Pure Ar, Robin C. Scott, Kevin D. Leedy, Burhan Bayraktaroglu, David C. Look, Yong-Hang Zhang
Physics Faculty Publications
Ga-doped ZnO was deposited by pulsed laser deposition at 200 °C on SiO2/Si, Al2O3, or quartz in 10 mTorr of pure Ar. The as-grown, bulk resistivity at 300 K is 1.8×10−4 Ω cm, three-times lower than that of films deposited at 200 °C in 10 mTorr of O2 followed by an anneal at 400 °C in forming gas. Furthermore, depth uniformity of the electrical properties is much improved. Mobility analysis shows that this excellent resistivity is mostly due to an increase in donor concentration, rather than a decrease in acceptor concentration. Optical …
Mobility Analysis Of Highly Conducting Thin Films: Application To Zno, David C. Look, K. D. Leedy, D. H. Tomich, B. Bayraktaroglu
Mobility Analysis Of Highly Conducting Thin Films: Application To Zno, David C. Look, K. D. Leedy, D. H. Tomich, B. Bayraktaroglu
Physics Faculty Publications
Hall-effect measurements have been performed on a series of highly conductive thin films of Ga-doped ZnO grown by pulsed laser deposition and annealed in a forming-gas atmosphere (5% H2 in Ar). The mobility as a function of thickness d is analyzed by a simple formula involving only ionized-impurity and boundary scattering and having a single fitting parameter, the acceptor/donor concentration ratio K = NA/ND. For samples with d = 3–100 nm, Kavg = 0.41, giving ND = 4.7×1020 and NA = 1.9×1020 cm−3. Thicker samples require a …
Ga-Related Photoluminescence Lines In Ga-Doped Zno Grown By Plasma-Assisted Molecular-Beam Epitaxy, Z. Yang, David C. Look, J. L. Liu
Ga-Related Photoluminescence Lines In Ga-Doped Zno Grown By Plasma-Assisted Molecular-Beam Epitaxy, Z. Yang, David C. Look, J. L. Liu
Physics Faculty Publications
Low-temperature photoluminescence (PL) and temperature-dependent Hall-effect (T-Hall) measurements were carried out in undoped and Ga-doped ZnO thin films grown by molecular-beam epitaxy. As the carrier concentration increases from 1.8×1018 to 1.8×1020 cm−3, the dominant PL line at 9 K changes from I1 (3.368–3.371 eV) to IDA (3.317–3.321 eV), and finally to I8 (3.359 eV). The dominance of I1, due to ionized-donor bound excitons, is unexpected in n-type samples but is shown to be consistent with the T-Hall results. We also show that IDA has characteristics of …
Ga-Doped Zno Films Grown On Gan Templates By Plasma-Assisted Molecular-Beam Epitaxy, H. J. Ko, Yanfang Chen, S. K. Hong, H. Wenisch, T. Yao, David C. Look
Ga-Doped Zno Films Grown On Gan Templates By Plasma-Assisted Molecular-Beam Epitaxy, H. J. Ko, Yanfang Chen, S. K. Hong, H. Wenisch, T. Yao, David C. Look
Physics Faculty Publications
We have investigated the structural and optical properties of Ga-doped ZnO films grown on GaN templates by plasma-assisted molecular-beam epitaxy. The carrier concentration in Ga-doped ZnO films can be controlled from 1.33×1018/cm3 to 1.13×1020/cm3. Despite high Ga incorporation, the linewidth of (0002) ω-rocking curves of Ga-doped ZnO films still lies in the range from 5 to 15 arc min. Photoluminescence (PL) spectra of Ga-doped ZnO films show dominant near-bandedge emission with negligibly weak deep-level emission, independent of carrier concentration. The PL spectrum exhibits a new emission line at 3.358 eV, which corresponds to …