Ultrathin chromium transparent metal contacts by pulsed dc magnetron sputtering

Optoelectronic technology frequently demands optically transparent materials. In this paper we present an overview of the development of ultrathin chromium films of above 80% optical transparency and 10(2)-10(3) mu Omega cm resistivity using bipolar pulsed dc magnetron sputtering. The surface morphology and film resistivity are investigated using atomic force microscopy (AFM) and four point probe, respectively. The variation of the electrical properties of the film with thickness, pulse duty cycle and target power are examined. An optimal experimental condition is suggested for developing transparent metal contacts, which can be used for the realisation of optoelectronic devices including organic light-emitting diodes on flexible, low cost polymeric substrates. This process does not require high temperature and post-deposition annealing unlike other transparent conducting oxides. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim