Author(s)

Rongbin Ye, Koji Ohta, Mamoru Baba

Faculty of Engineering, Iwate University, Morioka, Japan.

Organic thin film transistors based on an F₁₆CuPc/α6T pn heterojunction have been fabricated and analyzed to investigate the temperature dependence of electrical properties and apply in temperature sensors. The mobility follows a thermally activated hopping process. At temperatures over 200 K, the value of thermal activation energy (E_A) is 40. 1 meV, similar to that of the single-layer device. At temperatures ranging from 100 to 200 K, we have a second regime with a much lower E_A of 16.3 meV, where the charge transport is dominated by shallow traps. Similarly, at temperatures above 200 K, threshold voltage (V_T) increases linearly with decreasing temperature, and the variations of V_T of 0.185 V/K is larger than the variation of V_T (~0.020 V/K) in the single layer devices. This result is due to the interface dipolar charges. At temperatures ranging from 100 K to 200 K, we have a second regime with much lower variations of 0.090 V/K. By studying gate voltage (V_G)-dependence temperature variation factor (k), the maximum value of k (~0.11 dec/K) could be obtained at V_G = 5 V. Furthermore, the pn heterojunction device could be characterized as a temperature sensor well working at low operating voltages.

Organic Thin Film Transistors, pn Heterojunction, Temperature Dependence, Temperature Sensors

Ye, R. , Ohta, K. and Baba, M. (2016) Temperature Dependence of Electrical Properties of Organic Thin Film Transistors Based on pn Heterojuction and Their Applications in Temperature Sensors. Journal of Computer and Communications, 4, 10-15. doi: 10.4236/jcc.2016.45002.