Effect of ligand self-assembly on nanostructure and carrier transport behaviour in CdSe quantum dots

Different LB films of poly(octadecene-co-maleic anhydride), PMAO, poly(styrene-co-maleic anhydride) partial 2 butoxy ethyl ester cumene terminated, PS-MA-BEE, and Gemini surfactant ethyl-bis(dimethyl octadecylammonium bromide), 18-2-18, have been used to study the effect of the substrate coating on the surface self-assembly of CdSe quantum dots (QDs). Results show that all the “coating molecules” avoid the 3D aggregation of QDs observed when these nanoparticles are directly deposited on mica. Different morphologies were observed depending on the molecules used as coatings, and this was related to the surface properties, such as wetting ability, and the morphology of the coating LB films.

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HIGHLY ORDERED MICRO-ARRAYS OF CdSe QUANTUM DOTS ON CHEMICALLY PATTERNED SUBSTRATES

International Journal of Nanoscience ◽

10.1142/s0219581x09005815 ◽

2009 ◽

Vol 08 (01n02) ◽

pp. 119-122

Author(s):

LI ZHANG ◽

HUA-YAN SI ◽

HUA XU ◽

HAO-LI ZHANG ◽

YU-QING XIONG

Keyword(s):

Quantum Dots ◽

Cadmium Selenide ◽

Self Assembly ◽

Microcontact Printing ◽

Cdse Quantum Dots ◽

Two Dimensional ◽

Liquid Interfaces ◽

Patterned Substrates ◽

Cdse Qds ◽

Ordered Arrays

Highly ordered arrays consisting uniform fluorescent cadmium selenide ( CdSe ) quantum dots (QDs) ring or dot structures were obtained by self-assembly of QDs on chemically patterned substrates. In this method, Au substrates with alternating hydrophobic and hydrophilic square patterns are firstly fabricated by microcontact printing, which allows water droplets to condense on the hydrophilic regions to provide two-dimensional template arrays. The CdSe QDs are then assembled at the liquid/liquid interfaces to give uniform micro or nanostructures. The shape and size of the rings and dots can be tailored by controlling the relative evaporation speed of the water and the organic solvents. The obtained nanostructures have ideal topography to avoid substrate-induced fluorescence quenching.

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Measuring photoluminescence spectra of self-assembly array nanowire of colloidal CdSe quantum dots using scanning near-field optics microscopy

Functional Materials Letters ◽

10.1142/s1793604716500405 ◽

2016 ◽

Vol 09 (03) ◽

pp. 1650040 ◽

Cited By ~ 7

Author(s):

Zhongchen Bai ◽

Licai Hao ◽

Zhengping Zhang ◽

Shuijie Qin

Keyword(s):

Quantum Dots ◽

Self Assembly ◽

Near Field ◽

Porous Titanium ◽

Periodic Array ◽

Main Peak ◽

Cdse Quantum Dots ◽

Cdse Qds ◽

Near Field Optics ◽

Assembly Method

A novel periodic array CdSe nanowire is prepared on a substrate of the porous titanium dioxide by using a self-assembly method of the colloidal CdSe quantum dots (QDs). The experimental results show that the colloidal CdSe QDs have renewedly assembled on its space scale and direction in process of losing background solvent and form the periodic array nanowire. The main peak wavelength of Photoluminescence (PL) spectra, which is measured by using a 100-nm aperture laser beam spot on a scanning near-field optics microscopy, has shifted 60 nm with compared to the colloidal CdSe QDs. Furthermore, we have measured smaller ordered nanometer structure in thin QDs area as well, a 343-nm periodic nanowire in thick QDs area and the colloidal QDs in edge of well-ordered nanowire.

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