Strong piezoresistance effect of small molecule organic semiconductors

In this paper, we report on the strong piezoresistance effect on small molecule organic semiconductors. We fabricated and measured the indium-tin-oxide (ITO)/tris(8-hydroxyquinoline) aluminium (Alq, 80 nm) (or bathocuproine (BCP, 70 nm))/Al devices. In the simple devices, we measured the current under constant bias and square wave pulses with a load-produced varying pressure applied on the devices. The current shows a high sensitivity to the pressure. The related mechanism is also discussed. Our results clearly demonstrate that some of the small molecule organic semiconductors show potential as sensitive materials to be used in a tactile sensor. The sensor could be used in an artificial 'electronic skin' for future robots used in daily life for housekeeping or entertainment purposes.