Electro ↔ thermal coupling method to simulate the two-way interaction between heat generation and current flow in OLEDs and solar cells.

Case Studies

Calculating the Temperature Distribution in Optoelectronic Devices

Under standard operation, the current flowing inside an OLED or solar cell tends to heat up the device because of Joule heating. Laoss can calculate the position dependent temperature in the device and correlate the potential distribution (1) with the distribution of the temperature (2). Heat generation and current flow is a two-way iteration, that can be simulated with laoss.

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Map of the potential at the top electrode of a 10x10 cm2 OLED without metal grid


Explaining non-ideal I-V Characteristics in OLEDs and Solar Cells

In a two-way electrothermal coupling, heat is generated due to current flow. Meanwhile, the electrical conductivity inside the semiconductor stack increases with the rising temperature. With a two-way electrothermal model , laoss can calculate the temperature distribution in an operating device (1) and explain the origin of s-shaped current-voltage characteristics (2) due to a positive-feedback effect (increasing temperature ↔ increasing current ↔ increasing temperature). In OLEDs and solar cells the current density may increase even if the applied voltage decreases, because the temperature increases at the same time.

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