Ain’t we expecting alot from organic transistors: flexible electronics, inkjet-printed microchips and so on. But one reason that they’ve yet to hit the market big time is that their electronic behavior is hard to pin down and, even worse, seems to change with time. What’s going on?
Bertram Batlogg and buddies from the Swiss Federal Institute of Technology in Zurich are among those who are slowly teasing these characteristics apart, particularly with pentacene, the most promising organic semiconductor.
One thing they know is important is the mobility of charge carriers, how easily they can move around the structure. In pentacene, this seems to change with time and Batlogg and pals think they’ve worked out why.
It looks as if pentacene heals itself at room temperature, that is it corrects the defects within its structure. What the Swiss team has found is that oxygen and nitrogen seem to interfere with the healing process, which also explains why various labs have measured the phenomenon so differently.
Now Batlogg says he can standardize the process of healing (or self annealing, as it is called) by carrying it out in a vacuum at room temperature. This should guarantee a uniform quality of pentacene based-chips in future.
So keep ‘em peeled for functional crisp packets and edible microchips. Them plastic chips are a-comin’.
Ref: arxiv.org/abs/0711.1457: Defect Healing at Room Temperature in Pentacene Thin Films and Improved Transistor Performance