Temperature-Dependent Efficiency Droop in GaN-Based Blue LEDs

Temperature-Dependent Carrier Recombination and Efficiency Droop of AlGaN Deep Ultraviolet Light-Emitting Diodes

“…1(a), which reveals a fact that both the T-droop and J-droop present a severe extent at the high current injection. We therefore deduce that the decrease in EQE is related to the concentration-rich and high-thermal-energy carriers, which probably exacerbate the Auger recombination and the carrier leakage, because of the thermal emission, large band offset caused by AlGaN barriers, and numerous defects in active layers [19]. The T-droops respect to 280 K as a function of temperature are also showed in Fig.…”

“…Furthermore, considering that values of m below 2/3, we conjecture that the carrier leakage out of the active region, a multi-carrier loss mechanism, is brought into play as the current beyond 250 mA. The leakage may behaves a collection of various forms of non-radiative procedure, including thermionic emission of carriers out of MQWs, overflowing carriers not being captured by MQWs, and defect-assisted carrier tunneling [19].…”

Efficiency Models for GaN-Based Light-Emitting Diodes: Status and Challenges

“…In fact, the QW carrier density is known to be non-uniform across a multi-quantum well active region and may even vary inside each QW due to current crowding and/or QW non-uniformities. Various groups proposed modified ABC models, e.g., to account for a reduced active volume [ 43 ], inhomogeneous carrier distribution [ 44 ], electron leakage [ 36 , 45 ], photon quenching [ 46 ], multi-level defects [ 47 ], trap-assisted Auger recombination [ 48 ], built-in fields [ 49 ], or temperature effects [ 45 , 50 , 51 ]. In any case, ABC models serve as an important bridge between experiment and theory [ 52 ].…”

Multichannel sequential display LED driver with optimal transient performance and efficiency via synchronous integral control

“…The efficiency of the driver circuit was computed from measurements of the average current of the power supply, the actual input voltage, the output voltage and the average LED current. Due to the temperature‐dependent I – V curve of the LEDs [25–28], it takes about 5–10 min for the readings to reach steady‐state values, after the beginning of each test. Fig.…”