Failure resistance of amorphous silicon transistors under extreme in-plane strain

We have applied strain on thin-film transistors (TFTs) made of hydrogenated amorphous silicon on polyimide foil. In tension, the amorphous layers of the TFT fail by periodic cracks at a strain of ∼0.5%. In compression, the TFTs do not fail when strained by up to 2%, which is the highest value we can set controllably. The amorphous transistor materials can support such large strains because they lack a mechanism for dislocation motion. While the tensile driving force is sufficient to overcome the resistance to crack formation, the compressive failure mechanism of delamination is not activated because of the large delamination length required between transistor layers and polymer substrate.