Atomistic analysis of Auger recombination in c-plane (In,Ga)N/GaN quantum wells: Temperature-dependent competition between radiative and nonradiative recombination
Atomistic analysis of Auger recombination in c-plane (In,Ga)N/GaN quantum wells: Temperature-dependent competition between radiative and nonradiative recombination
复制标题
DOI：
10.1103/physrevb.105.195307
复制
发表时间：
2022-05-12
影响因子：
3.7
通讯作者：
Schulz, Stefan
中科院分区：
文献类型：
--
作者：
McMahon, Joshua M.;Kioupakis, Emmanouil;Schulz, Stefan
用原子论方法研究了In(In)含量分别为10%、15%和25%的c面(In，Ga)N/GaN量子阱中俄歇竞争和辐射复合的温度依赖性。该模型考虑了合金的随机波动以及应变和内置场的相关波动。我们的研究表明，总的俄歇复合速率与温度的关系很弱；在温度为300K，载流子密度为n(3D)=3.8×10(18)cm(-3)时，我们发现总的俄歇系数在接近6×10(-30)cm(-30)cm(6)/S(10%In)的范围内接近3×10(-31)cm(6)/S(25%In)，因此大到足以显著影响(In，Ga)N系统的效率。我们的计算表明，空穴-空穴-电子俄歇速率主导了所研究的三种In含量的总和；但是，当In含量增加到25%时，空穴-空穴-电子和电子-电子-空穴贡献之间的相对差异减小。我们的研究进一步揭示了(In，Ga)N基发光二极管的“热下降”(即，在固定载流子密度下，随着温度的升高，内部量子效率随温度的升高而降低)的来源。我们发现辐射和非辐射(俄歇)复合的比率在与热下垂相关的温度范围内增加(>；=300K)，这表明在c平面(In，Ga)N/GaN量子阱中，这些过程之间的竞争并不是驱动这种下垂效应的原因。这一发现与最近的实验研究一致。
We present an atomistic theoretical study of the temperature dependence of the competition between Auger and radiative recombination in c-plane (In,Ga)N/GaN quantum wells with indium (In) contents of 10%, 15%, and 25%. The model accounts for random alloy fluctuations and the connected fluctuations in strain and built-in field. Our investigations reveal that the total Auger recombination rate exhibits a weak temperature dependence; at a temperature of 300 K and a carrier density of n(3D) = 3.8 x 10(18) cm(-3), we find total Auger coefficients in the range of approximate to 6 x 10(-30) cm(6)/s (10% In) to approximate to 3 x 10(-31) cm(6)/s (25% In), thus large enough to significantly impact the efficiency in (In,Ga)N systems. Our calculations show that the hole-hole-electron Auger rate dominates the total rate for the three In contents studied; however, the relative difference between the hole-hole-electron and electron-electron-hole contributions decreases as the In content is increased to 25%. Our studies provide further insight into the origin of the "thermal droop" (i.e., the decrease in internal quantum efficiency with increasing temperature at a fixed carrier density) in (In,Ga)N-based light-emitting diodes. We find that the ratio of radiative to nonradiative (Auger) recombination increases in the temperature range relevant to the thermal droop (>= 300 K), suggesting that the competition between these processes is not driving this droop effect in c-plane (In,Ga)N/GaN quantum wells. This finding is in line with recent experimental studies.