Liquid Ga–In–Sn Alloy Printing of GaInSnO Ultrathin Semiconductor Films and Controllable Performance Field Effect Transistors

Wide band gap semiconductor Ga2O3 is a high potential material for fabricating next-generation power electronics. However, the low conductivity and carrier mobility of Ga2O3 have been seen as large barriers for its practical application. For many years, the efficient and low cost doping process to enhance the conductivity of Ga2O3 has always been a technological challenge. Here, we report a one-step synthesis strategy to prepare Ga2O3 doped with In2O3 and SnO2 (GaInSnO) multilayers from the liquid Ga–In–Sn alloy surface. Large area, controllable thickness, and high conductivity GaInSnO multilayers can be facilely obtained by using van der Waals exfoliation at a low temperature of 200 °C. The printed GaInSnO multilayers are transparent and display band gaps above 4.5 eV. The field effect transistors (FETs) based on the printed GaInSnO multilayers show n-type switching with on/off ratio all exceeding 105, a maximum field-effect mobility (μeff) of 65.40 cm2 V–1 s–1, and a minimum subthreshold swing (SS) of 91.11 mV dec–1 at room temperature. With rising Ga concentration in GaInSnO multilayers, the μeff of a fabricated FET decreases, while the SS increases. The present method can be further extended to produce various doped Ga2O3 films and utilized to fabricate electronic and optoelectronic devices based on modified Ga2O3 in the coming time.