The objective of this study was to investigate an indirect method of measuring the average junction temperature of a
white organic light-emitting diode (OLED) based on temperature sensitivity differences in the radiant power emitted by
individual emitter materials (i.e., “blue,” “green,” and “red”). The measured spectral power distributions (SPDs) of the
white OLED as a function of temperature showed amplitude decrease as a function of temperature in the different
spectral bands, red, green, and blue. Analyzed data showed a good linear correlation between the integrated radiance for
each spectral band and the OLED panel temperature, measured at a reference point on the back surface of the panel. The
integrated radiance ratio of the spectral band green compared to red, (G/R), correlates linearly with panel temperature.
Assuming that the panel reference point temperature is proportional to the average junction temperature of the OLED
panel, the G/R ratio can be used for estimating the average junction temperature of an OLED panel.