Printed and Thin Film Transistors and Memory
A new range of transistors using thin films of organic or inorganic compounds as the semiconductors and gate dielectrics are being pursued by organizations in more than 30 countries. The new IDTechEx report “Printed and Thin Film Transistors and Memory” studies the technologies, applications and progress of more than 150 companies in this sector. Here Dr. Peter Harrop, chairman, summarizes some of the findings ( www.IDTechEx.com/tftc).
• 339 pages with 10 year forecasts and 2027 outlook
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• 135 tables & figures
• More than 150 company profiles
• Printed and thin film transistors and memory
What new electronic product is being researched by organizations in more than 30 countries but none have sold anything yet? It is of huge significance to everyone in the electronic, printing, merchandising and healthcare industries, to name just a few. It is the printed transistor. To be more precise, it is Thin Film Transistor Circuits (TFTCs) that do not employ traditional crystalline or amorphous silicon, germanium or gallium arsenide and that can therefore be deposited at high speeds onto low cost flexible substrates.
Flexible transistor circuits using new compounds
Traditionally, semiconductors are made as crystalline as possible to optimise their performance. The new transistors variously use thin films of organic or inorganic compounds as the semiconductors and gate dielectrics, enabling flexible transistor circuits. One printable inorganic semiconductor favoured by Toppan Printing and Tokyo Institute of Technology is an amorphous combination of InGaZnO, for example, and it can be cured at low temperature. Electrodes in the new transistors are sometimes metal but sometimes they consist of conductive organic compounds.
Similarities with old types of transistor
There are similarities with the old silicon chip and the amorphous silicon transistor array on the back of an LCD display today. The new transistors are Field Effect Transistors (FETs). Most use the forty year old geometry where the controlled current passes horizontally but some (e.g. ORFID Inc in the USA) use vertical geometry to reduce feature size, increase frequency and current carrying capacity and/or reduce cost. Almost all potential markets for these new transistors are for arrays of large numbers of transistors, not individual transistors. Putting p type and n type back to back in a Complementary Metal Oxide Semiconductor (CMOS) configuration is favoured with the new as with the old technology, for example, to save power. Although very high power versions for electrical use are also in prospect, they are not the largest potential market. Some of these circuits of hundreds to millions of transistors will involve other devices such as sensors, diodes and fuses deposited at the same time. All this is very similar to the old technologies. But there the similarities stop.