Researchers from Ruhr-University Bochum developed a new process to fabricate transparent ultra-thin silver films
A team of researchers from Ruhr-Universität Bochum and the University of Wuppertal devised a new process to develop transparent ultra-thin silver films that can help to build highly efficient solar cells and light-emitting diodes. The research was led by Professor Anjana Devi and Nils Boysen from the Bochum-based research group of Inorganic Materials Chemistry, in collaboration with Professor Thomas Riedl from the Chair of Electronic Devices in Wuppertal. The findings were published in the journal Angewandte Chemie on September 27, 2018.
According to Nils Boysen, precursors used for the fabrication of ultra-thin silver films are highly sensitive to air and light. Although silver precursors can be stabilized using fluorine, phosphorus, or oxygen, these elements tend to contaminate the thin films and the equipment used for the production. Boysen and his colleagues devised an alternative solution to address the problems associated with common silver precursors. The team developed a chemical silver precursor, in which silver is surrounded with an amide and a carbine. The new silver precursor is stable without elements such as fluorine, phosphorus, or oxygen. The team found that atomic layer decomposition can be used to apply a silver thin film on an electrode with the new precursor. The step involves transportation of gaseous precursor to the electrode and deposition of a silver film at the electrode as a layer with a thickness of a few atoms. Moreover, the thin size of atoms leads to a transparent silver film.
According to Anjana Devi, the new process can be operated under atmospheric pressure and at low temperatures, which enables its use for industrial production. A series of tests were performed to demonstrate that the thin silver films manufactured with the help of this new method are pure and electrically conductive. Thomas Riedl concluded that the successful synthesis of the new precursor facilitates development of ultra-thin silver films and constitutes a first step towards the production of new electrodes that can be used for highly efficient solar cells and light-emitting diodes.