A5060271093- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Perovskite Materials and Applications
- Nonlinear Optical Materials Studies
- Nanocluster Synthesis and Applications
- Semiconductor Quantum Structures and Devices
- Gold and Silver Nanoparticles Synthesis and Applications
- Photonic Crystals and Applications
- Magnetic properties of thin films
- Photonic and Optical Devices
- Spectroscopy and Quantum Chemical Studies
- Copper-based nanomaterials and applications
- Magnetic Properties and Applications
- ZnO doping and properties
- Quantum optics and atomic interactions
- Advanced Semiconductor Detectors and Materials
- Nanowire Synthesis and Applications
- 2D Materials and Applications
- Magneto-Optical Properties and Applications
- Machine Learning in Materials Science
- Laser-Ablation Synthesis of Nanoparticles
- Photochemistry and Electron Transfer Studies
- Semiconductor Lasers and Optical Devices
- Magnetic Properties of Alloys
- Molecular Junctions and Nanostructures
Nanyang Technological University
2016-2025
Bilkent University
2016-2025
National Nanotechnology Research Center
2023-2024
University of Duisburg-Essen
2019
Photonics (United States)
2018
Singapore Polytechnic
2018
University at Buffalo, State University of New York
2008-2016
New York University
2016
Turkish Aerospace Industries (Turkey)
2015
Ankara University
2014
Colloidal nanoplatelets (NPLs) have recently emerged as favorable light-emitting materials, which also show great potential optical gain media due to their remarkable properties. In this work, we systematically investigate the performance of CdSe core and CdSe/CdS core/crown NPLs having different CdS crown size with one- two-photon absorption pumping. The exhibit enhanced compared core-only increased cross section efficient interexciton funneling, is from core. One- pumped amplified...
Here, we systematically investigated the spontaneous and stimulated emission performances of solution-processed atomically flat quasi-2D nanoplatelets (NPLs) as a function their lateral size using colloidal CdSe core NPLs. We found that photoluminescence quantum efficiency these NPLs decreases with increasing while decay rate accelerates. This strongly suggests nonradiative channels prevail in NPL ensembles having extended size, which is well-explained by number defected subpopulation. In...
There has been a strong interest in solution-processed two-dimensional nanomaterials because of their great potential optoelectronics. Here, the absorption cross-section and molar extinction coefficient four five monolayer thick colloidal CdSe nanoplatelets (NPLs) having various lateral sizes are reported. The these NPLs corresponding coefficients found to strongly depend on area. An excellent agreement is observed between experimental results calculated values based small-particle light...
Doping of bulk semiconductors has revealed widespread success in optoelectronic applications. In the past few decades, substantial effort been engaged for doping at nanoscale. Recently, doped colloidal quantum dots (CQDs) have demonstrated to be promising materials luminescent solar concentrators (LSCs) as they can engineered providing highly tunable and Stokes‐shifted emission spectrum. However, existing CQDs that are aimed full spectrum LSCs suffer from moderately low efficiency,...
Solution-processed quantum wells, also known as colloidal nanoplatelets (NPLs), are emerging promising materials for optoelectronics. In this work, we report the synthesis and characterization of CdSe/CdTe core/crown NPLs exhibiting a Type-II electronic structure specific optical properties. Here, based on core-seeded approach, were synthesized with well-controlled CdTe crown coatings. Uniform epitaxial growth region was verified by using structural techniques including transmission electron...
Abstract Surface effects in atomically flat colloidal CdSe nanoplatelets (NLPs) are significantly and increasingly important with their thickness being reduced to subnanometer level, generating strong surface related deep trap photoluminescence emission alongside the bandedge emission. Herein, synthesis of highly luminescent two‐monolayer (2ML) NPLs a systematic investigation carrier dynamics these exhibiting broad covering visible region quantum yields reaching 90% solution 85% polymer...
In this work, we report the manifestations of carrier–dopant exchange interactions in colloidal Mn2+-doped CdSe/CdS core/multishell quantum wells. The carrier–magnetic ion interaction effects are tunable through wave function engineering. our well heterostructures, manganese was incorporated by growing a Cd0.985Mn0.015S monolayer shell on undoped CdSe nanoplatelets using atomic layer deposition technique. Unlike previously synthesized nanostructures, location Mn ions controlled with...
Unique electronic and optical properties of doped semiconductor nanocrystals (NCs) have widely stimulated a great deal interest to explore new effective synthesis routes achieve controlled doping for highly efficient materials. In this work, we show copper via postsynthesis partial cation exchange (CE) in atomically flat colloidal nanoplatelets (NPLs). Here chemical reactivity different dopant precursors, reaction kinetics, shape seed NPLs were extensively elaborated successful emission....
Amplified spontaneous emission of a colloidal quantum dot film is electronically controlled in practical device.
In this study, nonradiative energy transfer was investigated in solid thin films of colloidal nanoplatelets incorporating two different vertical thicknesses.
The synthesis and unique tunable optical properties of core/crown nanoplatelets having an inverted Type‐I heterostructure are presented. Here, colloidal 2D CdS/CdSe heteronanoplatelets grown with thickness four monolayers using seed‐mediated method. In this work, it is shown that the emission peak resulting can be continuously spectrally tuned between wavelengths core only CdS (421 nm) CdSe (515 same vertical thickness. these nanoplatelets, continuous enabled by adjusting lateral width...
In the past decade, colloidal quantum wells, also known as 2-D semiconductor nanoplatelets (NPLs), have been added to nanocrystal (NC) family. Through unique control of thickness with monolayer precision, these novel materials exhibit strong 1-D confinement that offers optical properties along possibility fabricating advanced heterostructures, which are not possible other quantum-confined nanostructures. The CdX (X = Se, S)-based NPLs provide high color purities, fast fluorescence lifetimes,...
Colloidal type-II heterostructures are believed to be a promising solution-processed gain medium given their spatially separated electrons and holes for the suppression of Auger recombination wider emission tuning range from visible near-infrared region. Amplified spontaneous (ASE) was achieved colloidal core/shell nanocrystals several years ago. However, due limited charge-transfer (CT) interfacial states minimal overlap electron hole wave functions, ASE threshold has still been very high....
Highly efficient aqueous quantum wells are obtained from composition-tuned gradient shells with monolayer precision.
Semiconductor colloidal quantum wells (CQWs) provide anisotropic emission behavior originating from their optical transition dipole moments (TDMs). Here, solution-processed well light-emitting diodes (CQW-LEDs) of a single all-face-down oriented self-assembled monolayer (SAM) film CQWs that collectively enable supreme level IP TDMs at 92% in the ensemble are shown. This significantly enhances outcoupling efficiency 22% (of standard randomly-oriented emitters) to 34% face-down LED. As result,...
Mn-doped CdS nanorods synthesized by solution phase chemistry demonstrate robust ferromagnetic properties at and above room temperature. The show large coercivity, possibly originating from the shape anisotropy. hysteresis measurements reveal strong temperature dependence. Possible origin of ferromagnetism is discussed.
This paper describes preparation of binary FePt−CdS hybrid nanoparticles by spontaneous heteroepitaxial nucleation and growth the CdS component onto FePt-seed in high-temperature organic solution. FePt with average sizes 4 9 nm were used as seeds. Lattice mismatch makes complete coating seed particles unfavorable, resulting peanut-like flower-like nanoparticles. The photoluminescence is quenched band edge emission observed nanoparticles, albeit substantially lower intensity than pure We...
Abstract Whispering gallery mode (WGM) resonators are shown to hold great promise achieve high‐performance lasing using colloidal semiconductor nanocrystals (NCs) in solution phase. However, the low packing density of such gain media phase results increased thresholds and poor stability these WGM lasers. To address issues, here optical quantum wells (CQWs) is proposed form high‐density close‐packed solid films constructed around a coreless fiber incorporating resulting whispering modes...
Abstract Transition metal doped colloidal nanomaterials (TMDCNMs) have recently attracted attention as promising nano‐emitters due to dopant‐induced properties. However, despite ample investigations on the steady‐state and dynamic spectroscopy of TMDCNMs, experimental understandings their performance in stimulated emission regimes are still elusive. Here, optical gain properties copper‐doped CdSe quantum wells (CQWs) systemically studied with a wide range dopant concentration for first time....
Impurity doping is a promising strategy to afford colloidal nanocrystals exhibiting novel optical, catalytic, and electronic characteristics. However, some significant properties of noble metal-doped (NMD-NCs) remain unknown. Here, we report the electroluminescence (EL) from NMD-NCs. By silver impurity into cadmium selenide quantum wells (CQWs), dual-emission emitters are achieved light-emitting diode (LED) with luminance 1,339 cd m−2 reported. In addition, proposed energy gap engineering...
In two-dimensional (2D) colloidal semiconductor nanoplatelets, which are atomically flat nanocrystals, the precise control of thickness and composition on atomic scale allows for synthesis heterostructures with well-defined electron hole wave function distributions. Introducing transition metal dopants a monolayer precision enables tailored magnetic exchange interactions between band states. Here, we use absorption based technique circular dichroism (MCD) to directly prove coupling charge...
Excitonics, an alternative to romising for processing information since semiconductor electronics is rapidly approaching the end of Moore's law. Currently, development excitonic devices, where exciton flow controlled, mainly focused on electric-field modulation or polaritons in high-Q cavities. Here, we show all-optical strategy manipulate a binary colloidal quantum well complex through mediation Förster resonance energy transfer (FRET) by stimulated emission. In spontaneous emission regime,...
We describe a study of the magneto-optical properties Ag+-doped CdSe colloidal nanoplatelets (NPLs) that were grown using novel doping technique. In this work, we used magnetic circularly polarized luminescence and circular dichroism spectroscopy to light-induced magnetism for first time in 2D solution-processed structures doped with nominally nonmagnetic Ag+ impurities. The excitonic polarization (PX) exciton Zeeman splitting (ΔEZ) recorded as function field (B) temperature (T). Both ΔEZ PX...