Highly Sensitive and Ambient Air-Processed Hybrid Perovskite TFT Temperature Sensor

We report a highly sensitive thin-film transistor (TFT)-based temperature sensor with an ambient air-processed organic-inorganic hybrid perovskite, methylammonium lead iodide (MAPbI
₃
), semiconductor. The threshold voltage of MAPbI
₃
TFTs shows a strong linear temperature dependency with a temperature coefficient of -200±10 mV/K - making them good temperature sensors. TFTs with an inorganic (PbI2)-rich or organic (MAI)-rich semiconductor exhibit less temperature sensitivity than those with the stoichiometric MAPbI
₃
film - thus attributing the high temperature sensitivity to trap states in the hybridized MAPbI
₃
perovskite structure. We show that ambipolar transport in MAPbI
₃
TFTs can be exploited to widen their temperature sensing window and demonstrate high sensing capability of a temperature sensor, consisting of a single MAPbI
₃
TFT in the diode configuration (with drain and gate shorted).