Material Design of New p-Type Tin Oxyselenide Semiconductor through Valence Band Engineering and Its Device...

This paper reports a new p-type tin oxyselenide (SnSeO), which was designed with the concept that the valence band edge from O 2p orbitals in the majority of metal oxides becomes delocalized by hybridizing Se 4p and Sn 5s orbitals. As the Se loading increased, the SnSeO film structures were transformed from tetragonal SnO to orthorhombic SnSe, which was accompanied by an increase in the amorphous phase portion and smooth morphologies. The SnSe_0.56O_0.44 film annealed at 300 °C exhibited the highest Hall mobility (μ_Hall), 15.0 cm² (V s)^-1, and hole carrier density (n_h), 1.2 × 10¹⁷ cm^-3. The remarkable electrical performance was explained by the low hole effective mass, which was calculated by a first principle calculation. Indeed, the fabricated field-effect transistor (FET) with a p-channel SnSe_0.56O_0.44 film showed the high field-effect mobility of 5.9 cm² (V s)^-1 and an I_ON/OFF ratio of 3 × 10². This work demonstrates that anion alloy-based hybridization provides a facile route to the realization of a high-performance p-channel FET and complementary devices.