The I–V characteristics of InAs/GaAs quantum dot laser

The I–V characteristics of an InAs/GaAs quantum dot (QD) laser diode have been investigated under both the high and low input current conditions. Under the low current condition, the I–V curve obeys the Shockley equation, from which the forbidden energy gap of the junction can be derived. On the other hand, in the high current range, the I–V characteristics violate the Shockley equation and the device tends to operate as a resistance. In addition, the I–V curve can be used to fit the temperature coefficient of the forward voltage, which is a critical parameter for determining the junction temperature of the laser diode.