LAUSR

Thin‐film transistors using metal oxide semiconductors are essential in many unconventional electronic devices. Nevertheless, further advances will be necessary to broaden their technological appeal. Here, a new strategy is reported to achieve high‐performance solution‐processed metal oxide thin‐film transistors (MOTFTs) by introducing a metallic micro‐island array (M‐MIA) on top of the MO back channel, where the MO is a‐IGZO (amorphous indium‐gallium‐zinc‐oxide). Here Al‐MIAs are fabricated using honeycomb cinnamate cellulose films, created by a scalable breath‐figure method, as a shadow mask. For IGZO TFTs, the electron mobility (µe) increases from ≈3.6 cm2 V−1 s−1 to near 15.6 cm2 V−1 s−1 for optimal Al‐MIA dimension/coverage of 1.25 µm/51%. The Al‐MIA IGZO TFT performance is superior to that of controls using compact/planar Al layers (Al‐PL TFTs) and Au‐MIAs with the same channel coverage. Kelvin probe force microscopy and technology computer‐aided design simulations reveal that charge transfer occurs between the Al and the IGZO channel which is optimized for specific Al‐MIA dimensions/surface channel coverages. Furthermore, such Al‐MIA IGZO TFTs with a high‐k fluoride‐doped alumina dielectric exhibit a maximum µe of >50.2 cm2 V−1 s−1 . This is the first demonstration of a micro‐structured MO semiconductor heterojunction with submicrometer resolution metallic arrays for enhanced transistor performance and broad applicability to other devices.