Electrothermal feedback in Organic Devices (EFOD)

• Applicant: Professor Dr. Sebastian Reineke
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 319059955

Organic semiconductors typically have low charge carrier mobility, supporting only limited current densities. Still, organic devices easily reach the level of Joule self-heating, simply because they have large area and thin layer thicknesses; the latter in the nanometer range. In contrast to standard inorganic semiconductors like silicon or gallium arsenide, they show a strong positive feedback between the power dissipation and the electrical conductivity, leading to nonlinear effects like thermal switching or negative differential resistance (NDR) happening already at fairly low positive temperature increments. This project aims to demonstrate and investigate such nonlinear self-heating effects in two functional device types: organic light-emitting diodes (OLEDs) and organic transistors (OTs). Key objective is a fundamental understanding of these nonlinear processes in organic devices, essential for future device and circuit design. Within this project, based on the fundamental insights gained, new strategies will be developed to circumvent limitations induced by Joule self-heating. In addition, the effect of electrothermal feedback will be explored to develop future functions and applications in organic devices.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Karl Leo
• Cooperation Partner: Dr. Matthias Liero