In the December 2015 issue of the journal "Advanced Energy Materials", a research report from Nanyang Technological University in Singapore has been published that deals with a possible ITO substitute in the form of silver grids.
Attractive replacement for ITO
According to the researchers, so-called silver grids are an attractive substitute for indium tin oxide (ITO) as a flexible transparent conductor. You already know that indium tin oxide is currently the most important, transparent, electrically conductive material contained in displays of touch screens, screens, solar cells, LEDs and OLEDs as well as liquid crystal displays. Which also makes it quite expensive due to the unrelenting demand. However, the high price is only one of the reasons why people have been looking for a suitable ITO substitute for some time.
The report ("Highly Stable Transparent Conductive Silver Grid/PEDOT:PSS Electrodes for Integrated Bifunctional Flexible Electrochromic Supercapacitors") published in the December issue aims to improve the electrochemical stability of the silver-based, transparent conductors. The result is a silver-grid / PEDOT:PSS hybrid film with high conductivity and excellent stability.
PSS hybrid film for flexible electrochromic applications
The polymer PEDOT:PSS is a transparent and highly conductive hole conductor material. The function of the PSS hybrid film for flexible electrochromic applications is demonstrated by the application of a layer of WO3 nanoparticles (tungsten oxide nanoparticles) on the silver lattice / PEDOT. This hybrid structure presents a large optical modulation of 81.9% at 633 nm, as well as fast switching and fast color efficiency (124.5 cm2 C-1).
Even more important, however, is the achievement of excellent electrochemical cycle stability (preservation of 79.1% of its original transmission modulation after 1000 cycles), as well as remarkable mechanical flexibility (optical modulation decay of only 7.5% after 1200 pressure bending cycles).
The film obtains an optical modulation of 87.7% and a specific capacitance of 67.2% at 10g A-1 compared to the initial values at a current density of 1A G-1. The high-performance grating Silver / PEDOT: PSS Hybrid Film shows promising properties for various applications in flexible electronics and optoelectronic components.
The full research article can be obtained at the URL given in our reference.
