At room temperature in the manufacturing of semiconductor components, such as electronic bulletin boards will make (electronic billboards) such a large-scale applications, as well as disposable RFID tags such ultra-low-cost applications possible. But most of the electron mobility transistors at room temperature rate is very low, numerical only 1% ^ 2 seconds per V (cm2/Vs).
Now, the U.S. Georgia Institute of Technology (Georgia Institute of Technology, Georgia Tech) researchers claimed that through the use of Carbon 60 (C60) film is Buck ─ ─ ball (buckyballs) or fullerenes (fullerenes) ─ ─ to create Transistors (transistor) of the channel (channel), found a can produce than the amorphous silicon (amorphous) 100 times faster at room temperature transistor manufacturing methods.
"We do not claim to be the first to create C60 transistors at room temperature laboratory," Georgia Tech Professor Bernard Kippelen said: "The results of our research and development innovation, is to prove that process at room temperature under a 3 ~ 5 cm2 / Vs such a high electron mobility, while access to good renewable (reproducibility), stability, low threshold voltage and high switching current ratio (on-off current ratios). "
Global research in the laboratory at room temperature process technology, in order to take advantage of cheap, high-yield rolling of the (roll-to-roll) printing press or inkjet printing technology to create large displays and, as such a low-cost RFID applications; so First, you do not need those expensive clean rooms, high-temperature treatment process.There are many ways and are trying to use organic materials in the production of transistors, but also attempt to use new materials to upgrade the electronic prescription to the rate of migration channels.
There are other research units have achieved higher than the Georgia Tech Research Group of the electron mobility, but more is through high-temperature process to make organic transistors. The U.S. industry has developed Kovio Although a inorganic silicon ink (inorganic silicon ink), through the inkjet printing to produce thin film transistor, but process is far higher than the temperature plastic substrates can bear the scope.
Although Georgia Tech and the R & D results, failed to achieve high-temperature process can reach the electron mobility (Kovio claimed that its electron mobility and polysilicon as good), they realized the electronic migration rate has gone beyond amorphous silicon. And the potential application of a technology, production is only 16 ms refresh rate requirements (refresh rate) of a service-type display (service display); they can use low-cost plastic substrates.
Over the past few years to improve the design basis, Kippelen said his research team has identified the need for high-temperature electron mobility to the best of materials and parameters: "Our research based on organic semiconductors for refining (purification ) And several years of experience in dealing with the foundation. And the gate dielectric (gate dielectric) and the choice of metal electrode, also played a key role. "
For your convenience, Georgia Tech Research Group is a model component in the manufacture of silicon-based board, but the researchers claimed that their use of the organic transistors C60 all the elements are made at room temperature. And transistors at room temperature for the metal electrode, is OLED, as well as with the use of plastic solar cells used in a transparent process (transparent process) deposition from the same technology.
"We are using the electrode mask (shadow masking) and thermal evaporation (thermal evaporation) process, in the top-level organic semiconductors made of;" Kippelen said: "Let through the metal source (source) and between the substrate Large enough to maintain the distance (three feet), can not substrates in the process of sedimentary overheating. "
Next, the researchers will explore manufacturing n channel and p channel transistors way to use organic materials at room temperature, manufacture active-matrix display for the CMOS inverter (inverters), ring oscillator (ring oscillator), logic gates And drives, and other similar auxiliary circuit. "Replace silicon-based plastic floor boards, but also our future part of a research project;" Kippelen said.
But manufacturers using C60 transistor channel still has a shortcoming there, that is, they are sensitive to oxygen, this means that the components must be in nitrogen environment. The researchers plan to re-formed through the fullerene molecules, and ways to vacuum packaging components to address these issues.