Platelet-in-Box Colloidal Quantum Wells: CdSe/CdS@CdS Core/Crown@Shell Heteronanoplatelets

Keleştemur, Yusuf
Erdem, Onur
Olutas, Murat
Gungor, Kivanc
Demir, Hilmi Volkan
Here, the CdSe/CdS@CdS core/crown@shell heterostructured nanoplatelets (NPLs) resembling a platelet-in-box structure are developed and successfully synthesized. It is found that the core/crown@shell NPLs exhibit consistently substantially improved photoluminescence quantum yield compared to the core@shell NPLs regardless of their CdSe-core size, CdS-crown size, and CdS-shell thickness. This enhancement in quantum yield is attributed to the passivation of trap sites resulting from the critical peripheral growth with laterally extending CdS-crown layer before the vertical shell growth. This is also verified with the disappearance of the fast nonradiative decay component in the core/crown NPLs from the time-resolved fluorescence spectroscopy. When compared to the core@shell NPLs, the core/crown@shell NPLs exhibit relatively symmetric emission behavior, accompanied with suppressed lifetime broadening at cryogenic temperatures, further suggesting the suppression of trap sites. Moreover, constructing both the CdS-crown and CdS-shell regions, significantly enhanced absorption cross-section is achieved. This, together with the suppressed Auger recombination, enables the achievement of the lowest threshold amplified spontaneous emission (approximate to 20 mu J cm(-2)) from the core/crown@shell NPLs among all different architectures of NPLs. These findings indicate that carefully heterostructured NPLs will play a critical role in building high-performance colloidal optoelectronic devices, which may even possibly challenge their traditional epitaxially grown thin-film based counterparts.


Conductive polymer composites and copolymers of pyrrole and N-vinylcarbazole
Geissler, Uwe; Hallensleben, Manfred L.; Toppare, Levent Kamil (Elsevier BV, 1991-4)
The synthesis of composites and copolymers of pyrrole and N-vinylcarbazole is described. Both insulating and conducting polymers of N-vinylcarbazole are utilized in the electroinitiated polymerization of pyrrole. The influence of coating either of the conducting polymers prior to the other on the percolating threshold is discussed. The initial presence of both monomers in the reaction medium leads to a copolymer, whereas consecutive electrode coatings from the monomer solution yield inhomogeneous composites...
Structural interpretation of gabbroic rocks in Agacoren Granitoid, central Turkey: field observations and aeromagnetic data
Kadioglu, Yk; Ates, A; Güleç, Nilgün Türkan (1998-03-01)
Gabbroic rocks crop out commonly in different localities of the Central Anatolian Crystalline Complex and are interpreted by many researchers as the remnants of a Neotethyan ophiolitic suite now observed as roof-pendants in the granitoids of the complex. In this study, the structural position of the gabbroic rocks within one of the granitoids of the Central Anatolian Crystalline Complex, namely the Agacoren Granitoid, is determined by geological and aeromagnetic data from the central part of the pluton. The...
Lateral Size-Dependent Spontaneous and Stimulated Emission Properties in Colloidal CdSe Nanoplatelets
Olutas, Murat; Guzelturk, Burak; Keleştemur, Yusuf; Yeltik, Aydan; Delikanli, Savas; Demir, Hilmi Volkan (2015-05-01)
Here, we systematically investigated the spontaneous and stimulated emission performances of solution-processed atomically flat quasi-2D nanoplatelets (NPLs) as a function of their lateral size using colloidal CdSe core NPLs. We found that the photoluminescence quantum efficiency of these NPLs decreases with increasing lateral size while their photoluminescence decay rate accelerates. This strongly suggests that nonradiative channels prevail in the NPL ensembles having extended lateral size, which is well-e...
KHAN, SAEED AHMAD; Akata Kurç, Burcu; Department of Micro and Nanotechnology (2022-8-22)
Metal-organic frameworks (MOFs) are an emerging class of crystalline porous materials that consist of metal clusters (nodes) connected by organic linkers (struts) to form a three-dimensional molecular framework. MOFs have attracted considerable attention in recent years owing to their exceptional properties. Due to their remarkable design flexibility, ultra-high porosity, large specific surface area, and tunable chemistry, MOFs are indispensable for potential applications in clean energy, gas adsorption, an...
Intrusive products of H2O and CO2 rich alkaline melt (Karakoç Magmatic Association): Significance in tethyan realm, Turkey
Toksoy Köksal, Fatma (null; 2012-10-01)
The Karakoç Magmatic Association (KMA) within the Central Anatolian Crystalline Complex (CACC) consists of ultramafic cumulates, layered gabbros and diorite. The KMA intruded the carbonate dominated upper part of the CACC as a network and includes host rock xenoliths. The KMA is characterized by abundance of Ca-rich phases (green diopside (Mg#=57-93), pargasite (Mg#=41-86), plagioclase (An=91-95), scapolite (Me=42-92), calcite) and Ca-free minerals (phlogopite (Mg#=71-76), alkali-feldspar). The accessories...
Citation Formats
Y. Keleştemur, O. Erdem, M. Olutas, K. Gungor, and H. V. Demir, “Platelet-in-Box Colloidal Quantum Wells: CdSe/CdS@CdS Core/Crown@Shell Heteronanoplatelets,” ADVANCED FUNCTIONAL MATERIALS, vol. 26, no. 21, pp. 3570–3579, 2016, Accessed: 00, 2021. [Online]. Available: