We cannot use silicon in electronics forever. It is not possible to push it much further and because the powerful and power efficient electronics is needed, we have to use a different material in the future. It seems that carbon nanotube transistors can be potentially quite good alternative but until now, they never achieved the performance levels of silicon and gallium arsenide.
The engineers from University of Wisconsin-Madison were capable to do that for the first time. Their carbon nanotube transistors achieved 1.9-times higher current than the silicon ones. Because of that, we can expect that the reasearch will continue and this material is going to replace silicon in the future. According to the measurements, it should be five times faster or five times more efficient than silicon transistors. It is because the small dimensions of carbon layers allow to change a current signal very quickly.
The problem is that extremely pure nanotubes are needed and all impurities can restrict their semiconducting abilities. Therefore, the scientists use a special polymer that can get rid off almost all metallic parts (only 0.01% remains). Because the polymer acts like insulator it has to be removed thereafter. Also the right alignment of nanotubes is needed in order to work properly.