Optical/electrical correlations in ZnO: The plasmonic resonance phase diagram. Issue 10 (30th July 2013)

• Record Type: Journal Article
• Authors: Look, D. C.; Droubay, T. C.; Chambers, S. A.
• Is Part Of: Physica status solidi. Volume 250:Issue 10(2013:Oct.)
• Page Start: 2118
• Page End: 2121
• Publication Date: 2013-07-30
• Subjects: Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201200968
• Languages: English
• ISSNs: 0370-1972

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pssb201200968-sec-0001" sec-type="section"> <p>The Drude equation for dielectric constant <italic>ϵ</italic>(<italic>E</italic>) depends on four parameters: <italic>ϵ</italic><sub>∞</sub>, effective mass <italic>m</italic>*, optical mobility <italic>µ</italic><sub>opt</sub>, and optical carrier concentration <italic>n</italic><sub>opt</sub>. By solving this equation at <italic>ϵ</italic>(<italic>E</italic><sub>res</sub>) = 0, we obtain a relationship between <italic>µ</italic><sub>opt</sub> and <italic>n</italic><sub>opt</sub> at constant plasmonic resonance energy <italic>E</italic><sub>res</sub> [or wavelength <italic>λ</italic><sub>res</sub> (µm) = 1.2395/<italic>E</italic><sub>res</sub> (eV)]. A family of <italic>µ</italic><sub>opt</sub> versus <italic>n</italic><sub>opt</sub> curves covering a range of <italic>λ</italic><sub>res</sub> values (including the limiting wavelength <italic>λ</italic><sub>res</sub> = ∞) constitutes a plasmonic resonance phase diagram (PRPD) for a semiconductor defined by only <italic>ϵ</italic><sub>∞</sub> and <italic>m</italic>*. The PRPD is a convenient instrument that allows an immediate <italic>prediction</italic> of <italic>λ</italic><sub>res</sub> from Hall‐effect measurements of <italic>µ</italic><sub>H</sub> and <italic>n</italic><sub>H</sub>. We apply the PRPD analysis to a series of ten ZnO samples grown by pulsed laser deposition at 200 °C in an ambient of 33%H<sub>2</sub>:67%Ar and annealed in 25 °C steps for 10 min in air at various temperatures from 400 to 600 °C. For the samples annealed at 550 °C or lower, the <italic>µ</italic><sub>H</sub>/<italic>n</italic><sub>H</sub> points yield predicted values of <italic>λ</italic><sub>res</sub> that range from 1.07 to 2.80 µm; however, the 575 and 600 °C samples are predicted to have no resonance at all. Reflectance curves for the eight samples annealed up to 550 °C decrease slowly from 6 eV down to about <italic>E</italic><sub>res</sub> = 0.5–1.15 eV, and then increase rapidly for <italic>E</italic> < <italic>E</italic><sub>res</sub>. In contrast, there is no such resonance‐related increase for the 575 and 600 °C samples. Satisfactory agreement is found between the reflectance minima and the Hall‐effect‐predicted values of <italic>λ</italic><sub>res</sub>.</p> </sec> </abstract>