Effects of lanthanum (La) loading on the structural,
optical, and electrical properties of tin monoxide (SnO) films were
examined as a p-type semiconducting layer. La loading up to 1.9 atom
% caused the texturing of the tetragonal SnO phase with a preferential
orientation of (101), which was accompanied by the smoother surface
morphology. Simultaneously, the incorporated La cation suppressed
the formation of n-type SnO2 in the La-doped SnO film and
widened its optical band gap. These variations allowed the 1.9 atom
% La-loaded SnO film to have a high hole mobility and carrier density,
compared with the La-free control SnO film. The superior semiconducting
property was reflected in the p-type thin-film transistor (TFT). The
control SnO TFTs exhibited the field-effect mobility (μSAT) and I
ON/OFF ratio of 0.29
cm2 V–1 s–1 and 5.4
× 102, respectively. Enhancement in the μSAT value and I
ON/OFF ratio was
observed for the TFTs with the 1.9 atom % La-loaded SnO channel layer:
they were improved to 1.2 cm2 V–1 s–1 and 7.3 × 103, respectively. The
reason for this superior performance was discussed on the basis of
smoother morphology, suppression of disproportionation conversion
from Sn2+ to Sn + Sn4+, and reduced gap-state
density.
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 SnSe0.56O0.44 film
annealed at 300 °C exhibited the highest Hall mobility (μHall), 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 SnSe0.56O0.44 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.
Metal–interlayer–semiconductor contact reduces metal-induced gap states, mitigating Fermi-level pinning at metal/semiconductor interface. Here, switching property of p-type SnO FET is enhanced by increasing electron Schottky barrier at off-state.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.