Recent developments in the field of transparent conductive oxide films for spectral selective coatings, electronics and photovoltaics

The material class of transparent conductive oxides (TCO) has shown to be of crucial importance for optoelectronic devices in the last decades. In particular the combination of metallic conductivity and high transmittance in the visible spectra has been an enabling factor for all types of flat panel displays and thin films solar cells. As a consequence, the well-known In2O3:Sn (ITO) is nowadays one of the most intense researched materials for industrial coating technologies. Today, we observe strong market pull towards even more advanced TCOs. Emerging products such as high performance thin film solar cells, active matrix OLED displays and high resolution LCDs, flexible displays, OLED/LED lighting and various automotive applications, such as the ice-free Low-E coated windshield, require TCO performances which cannot be met with the coating technology industrially available today. This paper gives an overview on our latest developments in this field. We report on the fundamental work towards new materials such as p-type active semiconductive oxides, a prerequisite for oxide based electronic circuits. Furthermore, we outline our concept of model based process development for large area processes and we present recent findings on high performance ZnO:Al films for a-Si:H/µc-Si:H thin film photovoltaics and on high power impulse magnetron sputtering (HIPIMS) of ITO for ice-free windshield applications for automobiles.