Research On The Performance Of Field-effect Transistors Based On P-channel CuAlO₂

Recently,metal oxide semiconductors have been intensively investigated as channel layers for the applications in thin-film transistors?TFTs?due to their remarkable electrical performance,high optical transparency and excellent uniformity.However,most of the reported metal oxide semiconductors were n-type and only a few p-type oxide materials had been proven to be applicable in electronic devices.However,p-type oxides are indispensable for the construction of the metal oxide based devices,such as solar cells,complementary logic circuits and p-n junctions.In these considerations,it is highly desirable to fabricate p-type oxide semiconductors with comparable electrical performance of n-type counterparts.In this report,ternary p-type CuAlO₂ semiconductor thin films were fabricated by sol-gel method and integrated as channel layers in TFTs.The electrical performances of CuAlO₂ TFTs,together with the characteristics of CuAlO₂ thin films annealed at various annealing temperatures were systematically studied.The pure-phase CuAlO₂ thin films were obtained at 800 ^oC in N₂ atmosphere.CuAlO₂ TFTs annealed at 900 ^oC based on high-k Al₂O₃ exhibit optimized electrical performance,including a hole mobility of 1.36cm²/Vs and on/off current ratio of¹×10⁵.One-dimensional metal-oxide nanofibers show great potentials as the basis for nano-device platforms due to their large surface to volume ratio and unique electrical properties.In this work,p-type CuAlO₂ nanofibers field-effect transistors?FETs?were fabricated by combining sol-gel and electrospinning process.The electrical performances of the FETs based on CuAlO₂ nanofibers annealed at various annealing temperatures were systematically studied.The FETs based on aligned CuAlO₂ nanofibers were demonstrated to exhibit superior electrical performance,compared to the disordered counterparts with the comparable nanofibers coverage.This work not only demonstrates the successful fabrication of high-quality p-type CuAlO₂semiconductor thin film and nanofibers by sol-gel process,but also provides guidelines for related ternary p-type oxide semiconductor material and device performance improvements.