Excitonic hopping-pinning scenarios in lithium niobate based on atomistic models: different kinds of stretched exponential kinetics in the same system
Excitonic hopping-pinning scenarios in lithium niobate based on atomistic models: different kinds of stretched exponential kinetics in the same system
复制标题
基于原子模型的铌酸锂激子跳跃钉扎场景：同一系统中的不同种类的拉伸指数动力学
DOI：
10.1088/1361-648x/ab9c5b
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Mirco Imlau
中科院分区：
文献类型：
--
作者：
Gabor Corradi;Andreas Krampf;Simon Messerschmidt;Laura Vittadello;Mirco Imlau
基于耦合过程与不同的随时间变化的衰减动力学模型，我们提出了一个关键的审查光致发光（PL）和瞬态吸收（TA）实验在未掺杂和Mg或Fe掺杂的铌酸锂，连同一个全面的解释可见光辐射和平行的非辐射衰减过程的时间尺度从50 ns到分钟。研究了移动的自陷激子和钉扎激子的动力学的相似性和特殊性，并与同一系统中跳跃极化子的动力学进行了比较。激子跳跃的激活能为10.18 eV，显示出支配的寿命和淬火的短PL组件高于100 K。激子和偶极钉扎缺陷之间的强相互作用解释了掺杂LiNbO 3中延迟TA组分的过高寿命和大的脱钉扎能量，而被钉扎激子的受限跳跃被认为在LiNbO 3：Mg中的强延迟PL中起作用，由于局部减少的电子-声子耦合而表现出窄的发射带。钉扎激子的原子模型，提出相应的电荷补偿偶极缺陷的掺杂剂掺入铌酸锂3理论预测，并系统地分配到附近的UV边缘观察到的吸收带。在这些频带中的激发直接导致钉扎激子状态，也证实了先前提出的两步激子衰减的情况下，铌酸锂：铁。在同成分LiNbO 3中，弱的本征亚80 ns发光被解释为钉扎在Nb-Li反位缺陷上的激子增强的电子-声子耦合的相反效应。在典型系统LiNbO 3中观察到的不同拉伸行为的比较提供了一个直观的物理过程的图片。这些发现不仅是相关的全息和非线性光学应用的铌酸锂3，但也普遍感兴趣的治疗拉伸指数或其他时间相关的动力学在复杂的凝聚系统，从纳米晶体和聚合物的液体和生物物理系统。
Based on a model of coupled processes with differently time-dependent decay kinetics we present a critical review on photoluminescence (PL) and transient absorption (TA) experiments in undoped and Mg or Fe-doped LiNbO 3, together with a comprehensive interpretation of visible radiative and parallel non-radiative decay processes on timescales ranging from 50 ns up to minutes. Analogies and peculiarities of the kinetics of mobile self-trapped and pinned excitons are investigated and compared with those of hopping polarons in the same system. Exciton hopping with an activation energy of≈ 0.18 eV is shown to govern the lifetime and quenching of the short PL component above 100 K. Strong interaction between excitons and dipolar pinning defects explains the exorbitant lifetimes and large depinning energies characterizing delayed TA components in doped LiNbO 3, while restricted hopping of the pinned excitons is proposed to play a role in strongly delayed PL in LiNbO 3: Mg exhibiting a narrowed emission band due to locally reduced electron–phonon coupling. Atomistic models of pinned excitons are proposed corresponding to charge-compensated dipolar defects predicted by theories of dopant incorporation in LiNbO 3 and are systematically assigned to absorption bands observed near the UV edge. Excitation in these bands is shown to lead directly to pinned exciton states confirming also the previously proposed two-step exciton-decay scenario in LiNbO 3: Fe. Weak intrinsic sub-80 ns luminescence in congruent LiNbO 3 is explained as an opposite effect of enhanced electron–phonon coupling for excitons pinned on Nb Li antisite defects. The comparison of the different observed stretching behaviors in the paradigmatic system LiNbO 3 provides an intuitive picture of the underlying physical processes. The findings are relevant not only for holographic and non-linear optical applications of LiNbO 3 but are of general interest also for the treatment of stretched exponential or other time-dependent kinetics in complex condensed systems ranging from nanocrystals and polymers to liquids and biophysical systems.
登录
查看更多内容
LiNbO 3 单晶中Nb Nb 4 和O-极化子的时间分辨光致发光光谱
影响因子：
3.7
作者：
T. Kämpfe;P. Reichenbach;A. Haußmann;A. Thiessen;T. Woike;R. Steudtner;L.M. Eng
通讯作者：
L.M. Eng
影响因子：
2.8
作者：
Freytag, Felix;Booker, Phillip;Imlau, Mirco
通讯作者：
Imlau, Mirco
Cd1−xMnxTe 混合晶体中 DX 中心 Kohlrausch-Williams-Watts 光电离作用下的弛豫时间分布特性
DOI：
--
发表时间：
2009
期刊：
Journal of Physics: Condensed Matter
影响因子：
--
作者：
J. Trzmiel;K. Weron;J. Janczura;E. Płaczek
通讯作者：
E. Płaczek
化学计量LiNbO3晶体的热释光研究
DOI：
--
发表时间：
2002
期刊：
影响因子：
--
作者：
M. Chirila;N. Garces;L. Halliburton;D. Evans;S. Basun;R. Meltzer;W. Yen;S. Rutkowski;D. Shumov;J. Cahill
通讯作者：
J. Cahill
脉冲诱导的瞬态蓝色吸收与铁掺杂铌酸锂中的长寿命激子态相关
影响因子：
2.8
作者：
Simon Messerschmidt;Björn Bourdon;David Brinkmann;Andreas Krampf;Laura Vittadello;Mirco Imlau
通讯作者：
Mirco Imlau