Khrebtov Artem I, Danilov Vladimir V, Kulagina Anastasia S, Reznik Rodion R, Skurlov Ivan D, Litvin Alexander P, Safin Farrukh M, Gridchin Vladislav O, Shevchuk Dmitriy S, Shmakov Stanislav V, Yablonskiy Artem N, Cirlin George E
Alferov University, Khlopinast. 8/3, 194021 St. Petersburg, Russia.
Emperor Alexander I St. Petersburg State Transport University, Moskovsky pr. 9, 191031 St. Petersburg, Russia.
Nanomaterials (Basel). 2021 Mar 5;11(3):640. doi: 10.3390/nano11030640.
The passivation influence by ligands coverage with trioctylphosphine oxide (TOPO) and TOPO including colloidal CdSe/ZnS quantum dots (QDs) on optical properties of the semiconductor heterostructure, namely an array of InP nanowires (NWs) with InAsP nanoinsertion grown by Au-assisted molecular beam epitaxy on Si (111) substrates, was investigated. A significant dependence of the photoluminescence (PL) dynamics of the InAsP insertions on the ligand type was shown, which was associated with the changes in the excitation translation channels in the heterostructure. This change was caused by a different interaction of the ligand shells with the surface of InP NWs, which led to the formation of different interfacial low-energy states at the NW-ligand boundary, such as surface-localized antibonding orbitals and hybridized states that were energetically close to the radiating state and participate in the transfer of excitation. It was shown that the quenching of excited states associated with the capture of excitation to interfacial low-energy traps was compensated by the increasing role of the "reverse transfer" mechanism. As a result, the effectiveness of TOPO-CdSe/ZnS QDs as a novel surface passivation coating was demonstrated.
研究了用三辛基氧化膦（TOPO）和包含胶体CdSe/ZnS量子点（QDs）的TOPO配体覆盖对半导体异质结构光学性质的钝化影响，该半导体异质结构是通过金辅助分子束外延在Si（111）衬底上生长的具有InAsP纳米插入的InP纳米线（NWs）阵列。结果表明，InAsP插入物的光致发光（PL）动力学对配体类型有显著依赖性，这与异质结构中激发转移通道的变化有关。这种变化是由配体壳层与InP NWs表面的不同相互作用引起的，这导致在NW-配体边界处形成不同的界面低能态，如表面局域化反键轨道和能量上接近辐射态并参与激发转移的杂化态。结果表明，与激发捕获到界面低能陷阱相关的激发态猝灭被“反向转移”机制作用的增强所补偿。结果证明了TOPO-CdSe/ZnS QDs作为一种新型表面钝化涂层的有效性。
