Pathways towards P-Type Oxide Layers for Optoelectronic Applications

State of the art optoelectronic applications such as thin film solar cells, flat panel displays, and light emitting diodes suffer from the non-availability of p-type oxide materials on the industrial scale. Novel technologies such as transparent electronics, UV light emitting diodes, and improved thin film solar cells using wide band gap p-type oxide layers as front contact will be available once p-type oxide layers with proper layer and interface properties can be obtained on an industrial scale. In this paper, we report on our progress towards p-type oxide layers for industrial applications. We address the first principles density functional theory modeling of ZnO based layers where a pathway towards p-conductivity is seen taking the nitrogen doping of grain boundaries into account. The second part of the paper is on the synthesis of p-type Delafossite layers such as CuCr1-xAlxO2:Mg by Sol-Gel and CuCrO2 by hollow cathodes gas flow sputtering. We report on the deposition processes and film properties obtained. Both methods reveal p-type conductivity by means of Seebeck-coefficient measurements.