Abstract
Carrier recombination behavior in c-plane GaN-based laser diodes (LDs) is numerically investigated by using the commercial software LASTIP. It is found that efficiency droop phenomenon does exist in GaN-based LDs before lasing, which is confirmed by experimental results. However, the current density corresponding to the peak efficiency of GaN-based LDs before lasing, Jmax, is nearly 40 A/cm2, which is much lower than that reported by other studies. The reported Jmax, measured from the cavity facet side is modulated by the absorption of quantum wells, which shifts the Jmax to a higher value. In addition, the currents due to various recombinations are calculated. It is found that Auger recombination affects the threshold current greatly, but it only plays a small role at high current injection levels.
Highlights
Efficiency droop phenomenon has been widely observed in III-nitride light-emitting diodes (LEDs) [1,2], which means that the internal quantum efficiency (IQE) of GaN-based LEDs increases with the injection current until it comes to the maximum, afterwards it drops steadily
Since Auger recombination is proportional to the third power of the carrier concentration, its influence was expected to be more severe in GaN-based laser diodes (LDs) which operate at a high current density of several kA/cm2 [10]
The normalized dP/dJ–J value is proportional to the IQE,the we cavity facet, emission to the IQE of GaN-based LDs will rise with increasing injection current, so the Jmax would be regard the values of dP/dJ
Summary
Efficiency droop phenomenon has been widely observed in III-nitride light-emitting diodes (LEDs) [1,2], which means that the internal quantum efficiency (IQE) of GaN-based LEDs increases with the injection current until it comes to the maximum, afterwards it drops steadily. GaN-based laser diodes (LDs) operate like LEDs before lasing and their efficiency droop phenomenon has been studied [4,5,6]. Lutgen et al reported that the current density corresponding to the peak efficiency of GaN-based LDs before lasing, Jmax , is 133 A/cm2 [6], which is much larger than that of typical GaN-based LEDs. Understanding the reason behind this could be helpful in studying the origin of efficiency droop and may provide a possible way to alleviate efficiency droop in GaN-based LDs. few studies have talked about this. Since Auger recombination is proportional to the third power of the carrier concentration, its influence was expected to be more severe in GaN-based LDs which operate at a high current density of several kA/cm2 [10].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
