High quality ZnO:Al transparent conducting oxide films synthesized by pulsed filtered cathodic arc deposition

Abstract

Aluminum-doped zinc oxide, ZnO:Al or AZO, is a well-known n-type transparent conducting oxide with great potential in a number of applications currently dominated by indium tin oxide (ITO). In this study, the optical and electrical properties of AZO thin films deposited on glass and silicon by pulsed filtered cathodic arc deposition are systematically studied. In contrast to magnetron sputtering, this technique does not produce energetic negative ions, and therefore ion damage can be minimized. The quality of the AZO films strongly depends on the growth temperature while only marginal improvements are obtained with post-deposition annealing.The best films, grown at a temperature of about 200°C, have resistivities in the low to mid 10 -4 Ω cm range with a transmittance better than 85% in the visible part of the spectrum. It is remarkable that relatively good films of small thickness (60 nm) can be fabricated using this method.

Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

“…Collisions of the Cd ions with oxygen will provide excitation, ionization, and kinetic energy to oxygen, which promotes oxidation of the Cd and formation of high quality CdO. The deposition process is "energetic" with contributions of both kinetic and potential energy to the film growth process [21,42]. Significant low-energy ion bombardment during growth enhances the atom mobility without causing damage to the lattice, resulting in high quality films.…”

“…Each cathode was enclosed by an alumina ceramic tube such that the cathode spots can operate only on the front surface [21]. Metallic cadmium (99.99% purity) and indium (99.99% purity) rods were used as the two cathodes.…”

“…PFCAD has been demonstrated to be a technology suitable to make high quality aluminum doped zinc oxide (AZO) films at relatively low temperature [21]. The obtained optical and electrical parameters are comparable to or slightly better than the best films obtained by other methods such as magnetron sputtering (MS) and PLD [21,22]. However, to the best of our knowledge, PFCAD has not been used to grow doped or undoped CdO thin films.…”

“…Compared with PLD, PFCAD produces similar quality films but is easier to scale up and more cost effective, which is crucial for large-area applications. PFCAD has been demonstrated to be a technology suitable to make high quality aluminum doped zinc oxide (AZO) films at relatively low temperature [21]. The obtained optical and electrical parameters are comparable to or slightly better than the best films obtained by other methods such as magnetron sputtering (MS) and PLD [21,22].…”

Structural, optical, and electrical properties of indium-doped cadmium oxide films prepared by pulsed filtered cathodic arc deposition

“…PFCAD is a lesser known technique but it has been utilized to grow high quality aluminum doped zinc oxide (AZO) films [29]. Excellent CdO:In films can also be obtained by the natural advantages of PFCAD [10,30].…”