Thermal sensitivity from current-voltage-measurement temperature characteristics in Au/n-GaAs Schottky contacts

We have measured the current-voltage-temperature (I-V-T) characteristics of the Au/n-GaAs/In Schottky barrier diodes (SBDs) to introduce their thermal sensitivity mechanism. The forward bias voltage variation with temperature (thermal sensitivity) of this SBDs has been studied at different constant current levels. The diode showed high and decisive thermal sensitivity up to a current level of 0.10 pA. The bias voltage-temperature (V-T) curves of the SBD have showed an excellent linear behavior at all current levels. The slope dV/dT = alpha or the thermal sensitivity coefficient alpha from the V-T curves decreased from 3.42 mV/K at 0.10 pA to 1.31 mV/K at 10 mA with increasing current level. Furthermore, the alpha versus current graph of the diode has given a straight line from 0.10 pA to 10 mA whose intercept alpha(0) and slope d alpha/dI values have been obtained as 2.65 mV/K and -0.081 mV/(AK). The linearity of the voltage vs temperature and the alpha vs current graphs is a very crucial key factor of a good thermal sensor in the thermal sensitivity.