Controlling the structures of organic semiconductor-quantum dot nanocomposites through ligand shell chemistry.
Controlling the structures of organic semiconductor-quantum dot nanocomposites through ligand shell chemistry.
复制标题
通过配体壳化学控制有机半导体-量子点纳米复合材料的结构。
DOI：
10.1039/d0sm01109f
复制
发表时间：
2020
期刊：
影响因子：
3.4
通讯作者：
Toolan DTW
中科院分区：
文献类型：
--
作者：
Toolan DTW
用活性有机配体官能化的纳米晶体量子点（QD）作为太阳能转换材料具有重要的前景，能够进行多激子过程，可以提高单结光伏器件的效率。小角X射线和中子散射（SAXS和SANS）被用来表征后的硫化铅量子点的结构与模型并苯甲酸，氢化肉桂酸和萘甲酸配体交换。结果表明，氢化肉桂酸和萘甲酸连接的量子点形成单层配体壳，而苯甲酸连接的量子点具有比单层更厚的配体壳。此外，形成一系列的纳米复合材料，通过这种并苯连接的量子点与有机小分子半导体[5，12-双（（三异丙基甲硅烷基）乙炔基）并四苯（TIPS-Tc）]的自组装进行了研究。这些材料代表了更广泛的功能太阳能材料;这里的重点是结构研究，而不是研究它们的光电功能。随着TIPS-Tc浓度的增加，接近溶解度极限，SANS数据显示形成了QD分形特征，其结构可能与扩散限制聚集机制一致。这些很可能充当TIPS-Tc结晶的非均质成核剂，产生含有QD和TIPS-Tc两者的附聚物。在TIPS-Tc晶体内，似乎存在三种不同的QD形态：（i）在微晶中心（充当成核剂的分形状QD聚集体），（ii）被捕获在生长的微晶内（产生有序为粘性硬球的QD特征），以及（iii）在晶体界面的外围处的聚集体QD的群体，其从生长的TIPS-Tc晶体排出。将QD：TIPS-Tc晶体暴露于DMF蒸气（已知能够从QD剥离配体的溶剂）改变了PbS-氢化肉桂酸和PbS-萘甲酸连接的QD聚集体特征之间的间距。相比之下，对于PbS-苯甲酸连接的QD，DMF蒸气暴露促进有序QD胶体晶体类型相的形成。因此，这项工作证明了不同的量子点配体化学如何控制量子点和有机小分子之间的相互作用，从而导致广泛不同的自组装过程。它突出了多尺度X射线和中子散射在表征这种复合材料的独特能力。
Nanocrystal quantum dots (QD) functionalised with active organic ligands hold significant promise as solar energy conversion materials, capable of multiexcitonic processes that could improve the efficiencies of single-junction photovoltaic devices. Small-angle X-ray and neutron scattering (SAXS and SANS) were used to characterize the structure of lead sulphide QDs post ligand-exchange with model acene-carboxylic acid ligands (benzoic acid, hydrocinnamic acid and naphthoic acid). Results demonstrate that hydrocinnamic acid and naphthoic acid ligated QDs form monolayer ligand shells, whilst benzoic acid ligated QDs possess ligand shells thicker than a monolayer. Further, the formation of a range of nanocomposite materials through the self-assembly of such acene-ligated QDs with an organic small-molecule semiconductor [5,12-bis((triisopropylsilyl)ethynyl)tetracene (TIPS-Tc)] is investigated. These materials are representative of a wider set of functional solar energy materials; here the focus is on structural studies, and their optoelectronic function is not investigated. As TIPS-Tc concentrations are increased, approaching the solubility limit, SANS data show that QD fractal-like features form, with structures possibly consistent with a diffusion limited aggregation mechanism. These, it is likely, act as heterogeneous nucleation agents for TIPS-Tc crystallization, generating agglomerates containing both QDs and TIPS-Tc. Within the TIPS-Tc crystals there seem to be three distinct QD morphologies: (i) at the crystallite centre (fractal-like QD aggregates acting as nucleating agents), (ii) trapped within the growing crystallite (giving rise to QD features ordered as sticky hard spheres), and (iii) a population of aggregate QDs at the periphery of the crystalline interface that were expelled from the growing TIPS-Tc crystal. Exposure of the QD:TIPS-Tc crystals to DMF vapour, a solvent known to be able to strip ligands from QDs, alters the spacing between PbS–hydrocinnamic acid and PbS–naphthoic acid ligated QD aggregate features. In contrast, for PbS–benzoic acid ligated QDs, DMF vapour exposure promotes the formation of ordered QD colloidal crystal type phases. This work thus demonstrates how different QD ligand chemistries control the interactions between QDs and an organic small molecule, leading to widely differing self-assembly processes. It highlights the unique capabilities of multiscale X-ray and neutron scattering in characterising such composite materials.
登录
查看更多内容
影响因子：
10.8
作者：
Baumgardner, William J.;Whitham, Kevin;Hanrath, Tobias
通讯作者：
Hanrath, Tobias
影响因子：
22
作者：
Futscher MH;Rao A;Ehrler B
通讯作者：
Ehrler B
影响因子：
16.6
作者：
Kroupa DM;Vörös M;Brawand NP;McNichols BW;Miller EM;Gu J;Nozik AJ;Sellinger A;Galli G;Beard MC
通讯作者：
Beard MC
影响因子：
6.9
作者：
Olson, J. D.;Gray, G. P.;Carter, S. A.
通讯作者：
Carter, S. A.
影响因子：
5.7
作者：
Davis, Nathaniel J. L. K.;Allardice, Jesse R.;Rao, Akshay
通讯作者：
Rao, Akshay