CdSe/CdSe1-xTex Core/Crown Heteronanoplatelets: Tuning the Excitonic Properties without Changing the Thickness

Download

index.pdf

Date

2017-03-01

Author

Keleştemur, Yusuf
Erdem, Onur
Olutas, Murat
Erdem, Talha
Usanmaz, Can Firat
Gungor, Kivanc
Demir, Hilmi Volkan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

63
views

32
downloads

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 well-defined shape and compositions by employing transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. By precisely tuning the composition of the CdSe1-xTex crown region from pure CdTe (x = 1.00) to almost pure CdSe doped with several Te atoms (x = 0.02), we achieved tunable excitonic properties without changing the thickness of the NPLs and demonstrated the evolution of type-II electronic structure. Upon increasing the Te concentration in the crown region, we obtained continuously tunable photoluminescence peaks within the range of similar to 570 nm (for CdSe1-xTex crown with x = 0.02) and similar to 660 nm (for CdSe1-xTex crown with x = 1.00). Furthermore, with the formation of the CdSe1-xTex crown region, we observed substantially improved photoluminescence quantum yields (up to similar to 95%) owing to the suppression of nonradiative hole trap sites. Also, we found significantly increased fluorescence lifetimes from similar to 49 up to similar to 326 ns with increasing Te content in the crown, suggesting the transition from quasi-type-II to type-II electronic structure. With their tunable excitonic properties, this novel material presented here will find ubiquitous use in various efficient light-emitting and-harvesting applications.

URI

https://hdl.handle.net/11511/92576

Journal

JOURNAL OF PHYSICAL CHEMISTRY C

DOI

https://doi.org/10.1021/acs.jpcc.6b11809

Collections

Department of Metallurgical and Materials Engineering, Article

Suggestions

OpenMETU
Core

Alloyed Heterostructures of CdSexS1-x Nanoplatelets with Highly Tunable Optical Gain Performance Keleştemur, Yusuf; Gungor, Kivanc; Usanmaz, Can Firat; Erdem, Onur; Demir, Hilmi Volkan (2017-06-01) 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 homogeneously alloyed CdSexS1-x core NPLs as a seed, we prepared CdSexS1-x/CdS core/crown NPLs, where CdS crown region is extended only in the lateral direction. With the sidewall passivation around inner CdSexS1-x cores) we achieved enhanced photoluminescence quantum yield (PL-QY) (reach...
N-Substituted aziridine-2-phosphonic acids and their antibacterial activities Khan, Rehan; Doğan, Özdemir; Guven, Kiymet (ACG Publications, 2020-04-01) N-substituted aziridine diethyl phosphonates were synthesized easily in two steps starting from vinyl phosphonate or acetyl phosphonate. The controlled mono hydrolysis without opening the aziridine ring under mild reaction conditions was achieved by alkaline solution of LiOH. The corresponding phosphoric acid lithium salt was desalted by the use of Amberlite IRC-50H(+) acting as an efficient and recyclable weakly acidic cation exchange promoter. Antimicrobial activity of the synthesized compounds was tested...
Electrical and Mechanical Properties of Polypropylene/Carbon Black Composites Kanbur, Yasin; Kucukyavuz, Zuhal (SAGE Publications, 2009-09-01) Polypropylene(PP)/carbon black(CB) composites at different compositions were prepared via melt blending of PP with CB. The effect of CB content on mechanical and electrical properties was studied. Test samples were prepared by injection molding and compression molding techniques. The effect of processing type on mechanical and electrical properties was also investigated. Composites become semi-conductive by addition of 2wt% CB. The relation between mechanical and electrical properties was discussed. The inf...
EMPIRICAL FORMULATION OF BRIDGE INDUCTANCE IN INDUCTIVELY TUNED RF MEMS SHUNT SWITCHES Topallı, Kagan.; ÜNLÜ, MEHMET; Atasoy, Halil İbrahim; Aydın Çivi, Hatice Özlem; Demir, Şimşek; AKIN, TAYFUN (2009-01-01) This paper presents a substrate independent empirical formulation for the bridge inductance of inductively tuned RF MEMS shunt switches, allowing a systematic design approach to tune their isolation bands. Inductive tuning of RF MEMS switches is achieved by inserting recesses in the ground plane and meanders to the bridges, allowing the tuning of the isolation band of the switch from the X-band to the mm-wave band. The bridge inductance is first extracted from parametric EM simulations of the RF MEMS shunt ...
Asymmetric synthesis of norbornene based 1,4-amino alcohol derivatives and applications in asymmetric transformations Sünbül, Murat; Tanyeli, Cihangir; Department of Chemistry (2005) The asymmetric synthesis of cis-1,4-aminoalcohols with norbornene backbone was performed starting with simple and cheap anhydride 30. Quinine-mediated desymmetrization of anhydride 30 with methanol resulted in (2S,3R)-(-)-cis-hemiester 31 (98% e.e.). Chemoselective amination with HMPTA and NH4OH followed by LAH reduction afforded (2S,3R)-(+)-36 and (2S,3R)-(-)-37, respectively. The amidoester (2S,3R)-(-)-32 was transformed into chiral ligand (2S,3R)-(-)-35 with Grignard reaction followed by LAH reduction. T...

Citation Formats

Y. Keleştemur et al., “CdSe/CdSe1-xTex Core/Crown Heteronanoplatelets: Tuning the Excitonic Properties without Changing the Thickness,” JOURNAL OF PHYSICAL CHEMISTRY C, vol. 121, no. 8, pp. 4650–4658, 2017, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/92576.