Browsing by Author "Kelestemur Y."
Now showing items 1-15 of 15
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Alloyed heterostructures of CdSexS1-x nanoplatelets with highly tunable optical gain performance
Kelestemur Y.; Dede, D.; Gungor K.; Usanmaz, C. F.; Erdem, O.; Demir, Hilmi Volkan (American Chemical Society, 2017)Here, we designed and synthesized alloyed heterostructures of CdSexS1-x nanoplatelets (NPLs) using CdS coating in the lateral and vertical directions for the achievement of highly tunable optical gain performance. By using ... -
CdSe/CdSe1-xTex core/crown heteronanoplatelets: tuning the excitonic properties without changing the thickness
Kelestemur Y.; Guzelturk, B.; Erdem, O.; Olutas M.; Erdem, T.; Usanmaz, C. F.; Gungor K.; Demir, Hilmi Volkan (American Chemical Society, 2017)Here we designed and synthesized CdSe/CdSe1-xTex core/crown nanoplatelets (NPLs) with controlled crown compositions by using the core-seeded-growth approach. We confirmed the uniform growth of the crown regions with ... -
Colloidal nanoplatelet/conducting polymer hybrids: excitonic and material properties
Guzelturk, B.; Menk, F.; Philipps, K.; Kelestemur Y.; Olutas M.; Zentel, R.; Demir, Hilmi Volkan (American Chemical Society, 2016)Here we present the first account of conductive polymer/colloidal nanoplatelet hybrids. For this, we developed DEH-PPV-based polymers with two different anchor groups (sulfide and amine) acting as surfactants for CdSe ... -
Exciton dynamics of colloidal semiconductor quantum well stacks
Erdem, O.; Guzelturk, B.; Olutas M.; Kelestemur Y.; Demir, Hilmi Volkan (Springer Netherlands, 2018)Colloidal semiconductor nanoplatelets (NPLs) have recently emerged as a new class of colloidal nanocrystals. NPLs are quasi two-dimensional nanocrystals having atomically flat surfaces and have unique properties such as ... -
Flexible and fragmentable tandem photosensitive nanocrystal skins
Akhavan S.; Uran, C.; Bozok, B.; Gungor K.; Kelestemur Y.; Lesnyak, V.; Gaponik N.; Eychmüller A.; Demir, Hilmi Volkan (Royal Society of Chemistry, 2016)We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential ... -
Fluorescent heterodoped nanotetrapods as synergistically enhancing positive and negative magnetic resonance imaging contrast agents
Sharma, V. K.; Alipour, A.; Soran-Erdem Z.; Kelestemur Y.; Aykut, Z. G.; Demir, Hilmi Volkan (American Chemical Society, 2016)In this work, we report Mn-Fe heterodoped ZnSe tetrapod nanocrystals (NCs) synthesized to synergistically enhance contrast in both T1- and T2-weighted magnetic resonance imaging (MRI). The proposed NCs were prepared using ... -
High-efficiency optical gain in type-II semiconductor nanocrystals of alloyed colloidal quantum wells
Guzelturk, B.; Kelestemur Y.; Olutas M.; Li, Q.; Lian, T.; Demir, Hilmi Volkan (American Chemical Society, 2017)Colloidal nanocrystals having controlled size, tailored shape, and tuned composition have been explored for optical gain and lasing. Among these, nanocrystals having Type-II electronic structure have been introduced toward ... -
Highly efficient nonradiative energy transfer from colloidal semiconductor quantum dots to wells for sensitive noncontact temperature probing
Olutas M.; Guzelturk, B.; Kelestemur Y.; Gungor K.; Demir, Hilmi Volkan (Wiley-VCH Verlag, 2016)This study develops and shows highly efficient exciton-transferring hybrid semiconductor nanocrystal films of mixed dimensionality comprising quasi 0D and 2D colloids. Through a systematic study of time-resolved and ... -
Near-unity emitting copper-doped colloidal semiconductor quantum wells for luminescent solar concentrators
Sharma, M.; Gungor K.; Yeltik A.; Olutas M.; Guzelturk, B.; Kelestemur Y.; Erdem, T.; Delikanli S.; McBride, J. R.; Demir, Hilmi Volkan (Wiley-VCH Verlag, 2017)Doping of bulk semiconductors has revealed widespread success in optoelectronic applications. In the past few decades, substantial effort has been engaged for doping at the nanoscale. Recently, doped colloidal quantum dots ... -
Observation of biexcitons in nanocrystal solids in the presence of photocharging
Cihan, A. F.; Martinez, P. L. H.; Kelestemur Y.; Mutlugun, E.; Demir, Hilmi Volkan (American Chemical Society, 2013)T In nanocrystal quantum dots (NQDs), generating multiexcitons offers an enabling tool for enhancing NQD-based devices. However, the photocharging effect makes understanding multiexciton kinetics in NQD solids fundamenta ... -
Platelet-in-Box Colloidal Quantum Wells: CdSe/CdS@CdS Core / Crown@Shell Heteronanoplatelets
Kelestemur Y.; Guzelturk, B.; Erdem, O.; Olutas M.; Gungor K.; Demir, Hilmi Volkan (Wiley-VCH Verlag, 2016)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 ... -
Quantum dot/light-emitting electrochemical cell hybrid device and mechanism of its operation
Frohleiks, J.; Wepfer, S.; Kelestemur Y.; Demir, Hilmi Volkan; Bacher, G.; Nannen E. (American Chemical Society, 2016)A new type of light-emitting hybrid device based on colloidal quantum dots (QDs) and an ionic transition metal complex (iTMC) light-emitting electrochemical cell (LEC) is introduced. The developed hybrid devices show light ... -
Stacking in colloidal nanoplatelets: tuning excitonic properties
Guzelturk, B.; Erdem, O.; Olutas M.; Kelestemur Y.; Demir, Hilmi Volkan (American Chemical Society, 2014)Colloidal semiconductor quantum wells, also commonly known as nanoplatelets (NPLs), have arisen among the most promising materials for light generation and harvesting applications. Recently, NPLs have been found to assemble ... -
Temperature-dependent emission kinetics of colloidal semiconductor nanoplatelets strongly modified by stacking
Erdem, O.; Olutas M.; Guzelturk, B.; Kelestemur Y.; Demir, Hilmi Volkan (American Chemical Society, 2016)We systematically studied temperature-dependent emission kinetics in solid films of solution-processed CdSe nanoplatelets (NPLs) that are either intentionally stacked or nonstacked. We observed that the steady-state ... -
Type-tunable amplified spontaneous emission from core-seeded CdSe/CdS nanorods controlled by exciton-exciton interaction
Kelestemur Y.; Cihan, A. F.; Guzelturk, B.; Demir, Hilmi Volkan (Royal Society of Chemistry, 2014)Type-tunable optical gain performance of core-seeded CdSe/CdS nanorods is studied via two-photon optical pumping. Controlling the exciton-exciton interaction by varying the core and shell size, blue-shifted and red-shifted ...