AVS 60th International Symposium and Exhibition
    Thin Film Thursday Sessions
       Session TF-ThP

Paper TF-ThP8
Effect of Tungsten Incorporation on the Structure and Optical Properties of β-Gallium Oxide Thin Films

Thursday, October 31, 2013, 6:00 pm, Room Hall B

Session: Thin Films Poster Session
Presenter: E.J. Rubio, The University of Texas at El Paso
Authors: E.J. Rubio, The University of Texas at El Paso
C.V. Ramana, The University of Texas at El Paso
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Gallium oxide (Ga2O3) finds attractive applications in luminescent phosphors, hightemperature sensors, antireflection coatings, and solar cells. With a band gap of ∼5eV, Ga2O3 has been recognized as a deep ultraviolet transparent conducting oxide, which makes the material a potential candidate for transparent electrode applications in UV optoelectronics. The present work was performed to study the effect of tungsten (W) incorporation on the crystal structure, chemical composition, surface morphology and optical properties of Ga2O3 films. Films were grown by co-sputtering keeping the sputtering power to Ga2O3-target constant (100 W) while varying the sputtering-power (PW) to W-target in a wide range (50-100 W) in order to vary W-concentration in the films. The samples were deposited on to Si(100) and quartz substrates in a growth temperature range of 500-800 ºC. It is seen that increasing W concentration alters the electronic structure of Ga2O3 while the crystal structure of β- Ga2O3 phase is retained. Spectrophotometry analysis indicates that the W-doped Ga2O3 films are single phase and transparent. Due to substituional nature, W ions incorporated form donor levels and, thus, allowing band gap reduction and conductivity enhancement of Ga2O3. The band gap showed a red-shift from ~5 eV to ~4 eV with highest concentration of W-incorporation into β- Ga2O3 films. The structure-property relationship as a function of W-concentration in Ga2O3 films is established.