Characterizing Joule Heating in Polymer Light‐Emitting Diodes Using a Scanning Thermal Microscope

Abstract

Scanning thermal microscopy (SThM) has been used to study Joule heating in conjugated polymer light‐emitting diodes (LEDs; see Figure). The operational temperature of the LED is found to be a strong function of device area: smaller LEDs exchange heat more efficiently with their surrounding environment. The results suggest that at high current density, Joule heating may be linked to device failure.