Indium-free transparent electrodes made of highly conductive PEDOT:sulphate using CVD method
Sprache des Vortragstitels:
The 2017 European Material Research Society Fall Meeting and Exhibitt, E-MRS 2017
Sprache des Tagungstitel:
Indium tin oxide (ITO) has become synonymous for transparent electrodes: massively consumed for displays, smart windows, LED?s and related gadgets. In particular indium remains strongly dependent on its availability rendering it prone to financial speculation, geopolitical fluctuations, and its abundance.
Here, we present an alternative transparent electrode consisting of a conductive polymer, namely, PEDOT: sulphate. We prepare thin films by oxidative Chemical Vapour Deposition (oCVD), a technique allowing control for at highest purity and highest morphological quality.
The processing technique delivers ordered, highly conducting films and excellent scalability (as it requires only a minimal amount of manpower, and omits the need for expensive solvents or vacuum systems).
As a result, processed films combine conductivities on par with ITO (4050 S cm-1) with transparency spanning the visible and the near infrared spectral regime (400-1800 nm). This delivers a stunning optical figure of merit of 10-2 ?-1 at 1800 nm (Haacke), where inorganic oxides are reflecting. Furthermore, the metal-like material sports a flat temperature-conductivity profile, retaining 81 % of its room-temperature value (3300 S cm-1 at 1.8 K).
Also of note, PEDOT: sulphate offers all the mentioned advantages at a low density of ? ~ 1.5 g cm-3 indicating its use in light weight applications. Combined with its chemical composition and dependence on abundant elements only, it presents a potential contender crucially needed for future optoelectronics.