Flexible Thermal Sensors Based on Organic Field-Effect Transistors with Polymeric Channel/Gate-Insulating and Light-Blocking Layers

Myeonghun Song; Jooyeok Seo; Hwajeong Kim; Youngkyoo Kim

doi:10.1021/acsomega.7b00494

Flexible Thermal Sensors Based on Organic Field-Effect Transistors with Polymeric Channel/Gate-Insulating and Light-Blocking Layers

ACS Omega. 2017 Jul 31;2(7):4065-4070. doi: 10.1021/acsomega.7b00494.

Authors

Myeonghun Song¹, Jooyeok Seo¹, Hwajeong Kim¹, Youngkyoo Kim¹

Affiliation

¹ Organic Nanoelectronics Laboratory and KNU Institute for Nanophotonics Applications (KINPA), Department of Chemical Engineering, School of Applied Chemical Engineering, and Priority Research Center, Research Institute of Advanced Energy Technology, Kyungpook National University, University Road 80, 41566 Daegu, Republic of Korea.

Abstract

Here, we report flexible thermal sensors based on organic field-effect transistors (OFETs) that are fabricated using polymeric channel and gate-insulating layers on flexible polymer film substrates. Poly(3-hexylthiophene) and poly(methyl methacrylate) were used as the channel and gate-insulating layers, respectively, whereas indium-tin oxide-coated poly(ethylene naphthalate) films (thickness = 130 μm) were employed as the flexible substrates. Aluminum-coated polymer films were attached on top of the channel parts in the flexible OFETs to block any influence by light illumination. The present flexible OFET-based thermal sensors exhibited typical p-type transistor characteristics at a temperature range of 25-100 °C, while the hole mobility of devices was linearly increased with the temperature. The drain current could be amplified at various temperatures by adjusting the gate and drain voltages. In particular, stable sensing performances were measured during the repeated approaching/retreating cycle with a heat source. The flexible OFET thermal sensors attached on human fingers could sense heat from human fingers as well as from approaching objects.