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

Wide band gap semiconductor Ga 2 O 3 is a high potential material for fabricating next-generation power electronics. However, the low conductivity and carrier mobility of Ga 2 O 3 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 Ga 2 O 3 has always been a technological challenge. Here, we report a one-step synthesis strategy to prepare Ga 2 O 3 doped with In 2 O 3 and SnO 2 (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 10 5, a maximum field-effect mobility (μ eff ) of 65.40 cm 2 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 μ eff of a fabricated FET decreases, while the SS increases. The present method can be further extended to produce various doped Ga 2 O 3 films and utilized to fabricate electronic and optoelectronic devices based on modified Ga 2 O 3 in the coming time.