Thin films made from transparent conducting oxides (TCO) are used in a variety of optoelectronic devices including flat panel displays (LCD), photovoltaic cells and hetero-junction solar cells, solar control glazing for smart windows, light-emitting diodes (LEDs), solid-state gas sensors, antistatic coatings, EMI shieldings, electronic ink, etc.
The most commonly used TCO is indium tin oxide (ITO) due to its high electrical conductivity and high light transmission. However, indium is a scarce metal and has two main problems. On the one hand, ITO is a scarce metal and has high price around $750/kg. On the other hand, this raw material is also considered limited available of supply and price volatility, leading to spot prices for indium reaching almost $1000/kg due to high demand.
Objectives:
- To produce an indium-free TCC with optical transparency >90% at 400nm and electrical resistivity <20Ω/square.
- To formulate an ink which is compatible with the appropriate printing process.
- To develop novel printing procedures, compatible with the ink technology, capable of achieving uniform layer thicknesses of 150nm and track width of <25μm (half that of current state-of-the-art).
- A patterned printed indium-free TCCs with calculated electrical resistivity <100Ω/square.
- Printed TCC films with the above characteristics, deposited on glass and plastic substrates. For plastic substrates, the goal will be to keep the bulk substrate temperature below 150°C.
- To achieve objective (v) with a projected cost of €7/m2 (compared to the current cost of 70/m2), on the basis of a techno-economic validation of the technology.
- To perform a lifecycle analysis of the indium-free conductive coating, in comparison to current ITO benchmark.
- To produce demonstrator PV and display devices using printed indium-free anodes, with performance characteristics equivalent to current devices.
