Determination of internal quantum efficiency in GaInN-based light-emitting diode under electrical injection: carrier recombination dynamics analysis

Abstract

We proposed a method to determine the internal quantum efficiency (IQE) of GaInN-based light-emitting diode (LED). For the accurate determination thereof, we carefully reviewed a conventional carrier rate equation and then proposed a set of advanced formulae, which can comprehensively explain the carrier dynamics in a modern GaInN-based LED. Based on our proposed formula, this convenient method to determine the IQE is presented. Next, to identify the proposed carrier rate equations and recombination dynamics, we investigated carrier lifetime. We also discuss the physical origins of IQE degradation in a modern GaInN-based LED such as efficiency droop and green gap.

Enhanced Device Performance of GaInN-Based Green Light-Emitting Diode with Sputtered AlN Buffer Layer

“…Note that the EQEs at 50 mA are estimated as ~15.8% and ~11.5% for LED A and LED B, respectively. Recently, we proposed a reliable and convenient method to determine the IQE of GaInN-based LEDs [38]. The method is based on finding an exact value of the light extraction efficiency (LEE) by analyzing the L-I curve with an advanced carrier dynamics equation, which obtains the IQE values by comparing the EQEs, i.e., IQE = EQE × LEE.…”

Identifying the cause of thermal droop in GaInN-based LEDs by carrier- and thermo-dynamics analysis

“…Note that the IQEs in Fig. 2 were evaluated by the method presented in our previous paper 3,30 . As expected, the IQE gradually decreases with elevating chamber temperature over the entire current range.…”

“…Meanwhile, recent studies revealed that recombinations that occurs outside the active region predominates at high-current injection in GaInN-based LEDs. In this study, we thus utilized AB + f ( n ) model 30 , 35 , 36 , which is frequently adopted to comprehensively explain recombinations occurring both inside and outside the active region. In this model, the IQE is written in terms of the carrier rate equation as following, where T is the temperature, A ( n,T ) and B ( n,T ) are the SRH nonradiative recombination and the bimolecular radiative recombination coefficient in MQWs.…”

“… 28 and 36 . Particularly, the C ( n , T ) n 3 is included in the IE because it consisted of not only the pure Auger recombination 37 , but also the phase-space filling (PSF) effect on the Auger recombination 30 , the phonon-assisted recombination 38 , the indirect Auger recombination 39 , the hot carrier generation 40 , and carrier emissions to the vacuum level 41 , which results in carrier recombination outside the active region. Figure 4 b shows the linear plot of the IEs as a function of driving current at various operating temperatures.…”

Измерение внутреннего квантового выхода излучения InGaN светодиода

“…Важнейшим параметром светодиодов, определяющим эффективность преобразования электрического тока в оптическое излучение, является внутренний квантовый выход. Этот параметр используется при оценке качества изготовления светодиодных гетероструктур, их энергетической эффективности, а также при исследовании механизмов спада эффективности излучения при больших токах и механизмов деградации светодиодов в процессе их испытаний [1][2][3][4][5]. Внутренний квантовый выход определяется как отношение числа фотонов, рожденных в активной области светодиода в единицу времени, к числу инжектированных в эту область электронов [1].…”