Field-effect transistor based on KTaO₃ perovskite

The field-effect transistor (FET) is the most fundamental device among all solid state devices based on transition metal oxides, and thus the fabrication of FETs using perovskite-related oxides for conducting channels is a first step in a large movement towards oxide electronics.
Nevertheless, only a small number of perovskite FETs with relatively low mobilities have been reported so far.

KTaO₃, an n-type semiconductor with a band gap of 3.8 eV, which, in single crystalline form, exhibits a relatively higher mobility of 30 cm²/V s at room temperature than other perovskites.

The FET fabricated on the heat-treated surface of a KTaO₃ single crystal showed accumulation-type behavior and reproducible n-channel transistor characteristics with a field-effect mobility more than 0.4 cm²/V s and an ON/OFF ratio greater than 10⁴ at room temperature.
The field-effect mobility was almost temperature independent down to 200 K. These results indicate that the Al₂O₃/KTaO₃ interface is worthy of further investigations as an alternative system of future oxide electronics.

Authors have demonstrated that KTaO₃ is one of the most promising materials for perovskite FET technology. This strongly inspires future research into oxide electronics.