Gas-Phase Formation of Highly Luminescent 2D GaSe Nanoparticle Ensembles in a Nonequilibrium Laser Ablation Process
Gas-Phase Formation of Highly Luminescent 2D GaSe Nanoparticle Ensembles in a Nonequilibrium Laser Ablation Process
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DOI：
10.3390/nano10050908
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发表时间：
2020-05-01
期刊：
影响因子：
5.3
通讯作者：
Mahjouri-Samani, Masoud
中科院分区：
文献类型：
--
作者：
Elafandi, Salah;Ahmadi, Zabihollah;Mahjouri-Samani, Masoud
在过去的几十年里，人们对层状二维（2D）材料的兴趣迅速上升，这是因为它们具有原子薄的2D结构限制，具有良好的光电和光子特性。当这些2D材料在横向尺寸上进一步限制为零维（0 D）结构时，可以形成具有新特性的2D纳米颗粒和量子点。在这里，我们报告了一种非平衡气相合成方法的化学计量形成的硒化镓（GaSe）纳米粒子合奏，可以潜在地作为量子点。我们表明，在氩气背景气体中的目标的激光烧蚀冷凝的激光产生的羽流，导致在气相中的亚稳态纳米粒子的形成。这些纳米颗粒沉积到基底上导致形成纳米颗粒集合体，然后对其进行后处理以结晶或烧结纳米颗粒。背景气体压力的影响，除了结晶/烧结温度，进行了系统的研究。扫描电子显微镜（SEM），透射电子显微镜（TEM），光致发光（PL）光谱，和时间相关的单光子计数（TCSPC）测量被用来研究的生长参数，形态和光学性能的制造的2D纳米粒子合奏之间的相关性。
Interest in layered two-dimensional (2D) materials has been escalating rapidly over the past few decades due to their promising optoelectronic and photonic properties emerging from their atomically thin 2D structural confinements. When these 2D materials are further confined in lateral dimensions toward zero-dimensional (0D) structures, 2D nanoparticles and quantum dots with new properties can be formed. Here, we report a nonequilibrium gas-phase synthesis method for the stoichiometric formation of gallium selenide (GaSe) nanoparticles ensembles that can potentially serve as quantum dots. We show that the laser ablation of a target in an argon background gas condenses the laser-generated plume, resulting in the formation of metastable nanoparticles in the gas phase. The deposition of these nanoparticles onto the substrate results in the formation of nanoparticle ensembles, which are then post-processed to crystallize or sinter the nanoparticles. The effects of background gas pressures, in addition to crystallization/sintering temperatures, are systematically studied. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, and time-correlated single-photon counting (TCSPC) measurements are used to study the correlations between growth parameters, morphology, and optical properties of the fabricated 2D nanoparticle ensembles.