Hybrid-Type Temperature Sensor Using Thin-Film Transistors

We have developed a hybrid-type temperature sensor using thin-film transistors. First, we evaluate temperature dependences of transistor characteristics and find that the temperature dependence of the off-leakage current is much larger than that of the on current. Next, we combine a transistor, capacitor, and ring oscillator to develop the hybrid-type temperature sensor and detect the temperature by measuring the oscillation frequency. The large temperature dependences of the off-leakage currents can be utilized, and simultaneously only a digital circuit is required to count the digital pulse.