Analysis of carrier transport and band tail states in p-type tin monoxide thin-film transistors by temperature dependent characteristics

Tin monoxide (SnO) has drawn much attention in recent years due to its high hole mobility, transparency, and potential for mass production. However, due to its metastable nature, the deposited film often contains multi-phases such as metallic tin and tin dioxide, which may degrade its electrical properties. Here, we presented the temperature dependent characteristics of p-type SnO thin-film transistors. The hole transport mechanism is dominated by band conduction at high temperatures and variable-range hopping at low temperatures. The maximum activation energy was found to be 308 meV, which denotes a bandgap of around 0.6 eV. The density of states was found to be 1.12 × 1021 cm−3 eV−1 at VG = −80 V, and 6.75 × 1020 cm−3 eV−1 at VG = 0 V, respectively.