<p> Thin films of chlorine (Cl) and copper (Cu) doped zinc selenide (Cl:ZnSe and Cu:ZnSe) were fabricated by pulsed laser deposition (PLD) with the goal of enabling a multilayered semiconductor structure for a mid-infrared (mid-IR) electrically excited laser. Doping of ZnSe is achieved by varying the mass ratio of zinc chloride (ZnCl<sub>2</sub>) or copper selenide (Cu<sub>2</sub>Se) to ZnSe precursors in starting pressed powder targets. Appropriate adjustment of the fraction of dopant precursor in the mixtures allows for the control of the dopant concentration, N<i><sub>D</sub></i>–N<i><sub> A</sub></i> for N<i><sub>D</sub></i> >> N<i><sub>A</sub></i> (or N<i><sub>A</sub></i>-N<i><sub>D</sub></i> for N<i><sub> A</sub></i> >> N<i><sub>D</sub></i>) in the thin films, where N<i><sub>D</sub></i> is the donor concentration and N<i><sub> A</sub></i> is the acceptor concentration. PLD is used to ablate the Cl:ZnSe or Cu:ZnSe targets, to produce thin films on gallium arsenide (GaAs) substrates. Impedance spectroscopy allows current-voltage and capacitance-voltage (C-V) characterization. Specifically Mott-Schottky measurements determine N<i><sub>D</sub></i>-N<i><sub>A</sub></i> (or N<i><sub> A</sub></i>-N<i><sub>D</sub></i>) of the fabricated thin film samples with comparisons to the nominal dopant concentration of the targets. The Mott-Schottky, 1/C<sup>2</sup> vs. V, measurements for determining N<i><sub>D</sub></i>-N<i><sub>A</sub></i> were calibrated against well-characterized silicon wafers with known values of N<i><sub> D</sub></i>. The goal of this project was to demonstrate a reliable method for controlling the dopant concentration in PLD-deposited Cl:ZnSe and Cu:ZnSe thin films. The results obtained allows for the fabrication of Cl:ZnSe and Cu:ZnSe thin films with known N<i><sub>D</sub></i>-N<i><sub> A</sub></i> for use in a mid-IR electrically-excited laser devices under development in our research group.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10787536 |
| Date | 23 May 2018 |
| Creators | Rhoades, Matthew W. |
| Publisher | The University of Alabama at Birmingham |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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