*3.1. Device Callibration*

Before the actual measurements, each of the investigated devices was calibrated on a cold plate for the forward current of 10 mA. The measured dependencies of diode voltage on temperature are presented in Figure 3a. The black markers and lines correspond to the module having the thermal pads of standard size (STP), whereas the lighter ones to the module with double size thermal pads (DTP). As can be seen in the chart, for each diode this dependence is fairly linear but the measured sensitivity values vary, substantially falling in the range of 1.46÷2.23 mV/K. This result suggests thermal models should be developed independently for each device.
