Electrical response to uniaxial tensile strain of a-Si:H TFTs fabricated on polyimide foils

The electro-mechanical response of amorphous silicon thin-film transistors fabricated on polyimide foil depends on the transistors’ strain history. As long as the tensile strain applied to the transistor is kept below the electrical failure strain, the sensitivity of the field-effect mobility to tensile strain weakens with increasing number of load cycles. Once electrical failure is reached, the electro-mechanical response is controlled by the duration for which the TFT was held at failure strain. TFTs held at the failure strain for several hours do not recover. TFTs held at failure strain for only a short period of time do recover, and one cannot distinguish their transfer characteristics from those of a virgin TFT. However, their electron mobility, while still increasing with rising tensile strain, responds more weakly to strain than a virgin TFT.