Sharu Kritika, Chattopadhyay Shashwata, Prajapati K N, Mitra J
School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala 695551, India.
J Chem Phys. 2023 Dec 28;159(24). doi: 10.1063/5.0171078.
Modeling light-matter interactions in hybrid plasmonic materials is vital to their widening relevance from optoelectronics to photocatalysis. Here, we explore photoluminescence (PL) from ZnO nanorods (ZNRs) embedded with gold nanoparticles (Au NPs). A progressive increase in Au NP concentration introduces significant structural disorder and defects in ZNRs, which paradoxically quenches defect related visible PL while intensifying the near band edge (NBE) emission. Under UV excitation, the simulated semi-classical model realizes PL from ZnO with sub-bandgap defect states, eliciting visible emissions that are absorbed by Au NPs to generate a non-equilibrium hot carrier distribution. The photo-stimulated hot carriers, transferred to ZnO, substantially modify its steady-state luminescence, reducing NBE emission lifetime and altering the abundance of ionized defect states, finally reducing visible emission. The simulations show that the change in the interfacial band bending at the Au-ZnO interface under optical illumination facilitates charge transfer between the components. This work provides a general foundation to observe and model the hot carrier dynamics and strong light-matter interactions in hybrid plasmonic systems.
模拟混合等离子体材料中的光与物质相互作用对于其从光电子学扩展到光催化的广泛应用至关重要。在此，我们研究了嵌入金纳米颗粒（Au NPs）的氧化锌纳米棒（ZNRs）的光致发光（PL）。金纳米颗粒浓度的逐步增加在氧化锌纳米棒中引入了显著的结构无序和缺陷，这看似矛盾地猝灭了与缺陷相关的可见PL，同时增强了近带边（NBE）发射。在紫外激发下，模拟的半经典模型实现了具有亚带隙缺陷态的氧化锌的PL，引发了被金纳米颗粒吸收的可见发射，从而产生非平衡热载流子分布。光激发的热载流子转移到氧化锌中，极大地改变了其稳态发光，缩短了近带边发射寿命并改变了电离缺陷态的丰度，最终减少了可见发射。模拟结果表明，光照下金 - 氧化锌界面处界面能带弯曲的变化促进了组分之间的电荷转移。这项工作为观察和模拟混合等离子体系统中的热载流子动力学和强光与物质相互作用提供了一个通用基础。
