Recombination kinetics of excitonic molecules and free excitons in intrinsic silicon
Recombination kinetics of excitonic molecules and free excitons in intrinsic silicon
复制标题
本征硅中激子分子和自由激子的复合动力学
DOI：
10.1016/0022-2313(70)90045-1
复制
发表时间：
1970
影响因子：
3.6
通讯作者：
J. Cuthbert
中科院分区：
文献类型：
--
作者：
J. Cuthbert
时间分辨光谱和发光衰减时间测量证明，在1.8 K时，纯硅中的激子分子（EM）和自由激子（FE）密度以不同的速率衰减。EM的衰减曲线显示出激发后亮度增加，随后是近似指数衰减，衰减时间为143nsec。FE衰减包括一个初始瞬态，随后是一个较长的非指数衰减。这些观测结果可以用一对耦合的微分方程来详细解释EM和FE密度的时间衰减。这些方程是基于Haynes用来解释EM重组谱的模型。理论和实验的衰减比较表明，EM的衰减时间为59 nsec，在1.8 K时，两个FE形成EM的截面约为2× 10−15 cm 2。基于这些数据，提出了一些论点，表明电磁的衰减主要是由非辐射的俄歇机制引起的，这是低辐射效率的原因。高温下的热解离效应可以半定量地解释。
Time-resolved spectra and luminescence decay-time measurements prove that at 1.8 K the excitonic-molecule (EM) and free-exciton (FE) densities decay at different rates in pure silicon. The decay profile of the EM shows a postexcitation increase in luminesence followed by an approximately exponential decay with a decay time of 143 nsec. The FE decay consists of an initial transient followed by a longer nonexponential decay. These observations can be explained in detail by a pair of coupled differential equations governing the time decay of the EM and FE densities. The equations are based on the model used by Haynes to explain the EM recombination spectrum. Comparison of the theoretical and experimental decays shows that the EM decay time is 59 nsec, and the cross section at 1.8 K for the formation of an EM from two FE's is about 2× 10− 15 cm 2. Based on these data, arguments are presented to show that the EM's decay primarily by a nonradiative Auger mechanism, which accounts for the low radiative efficiency. Thermal dissociation effects at higher temperatures can be semiquantitatively accounted for.