PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/397
Browse
4 results
Search Results
Article Citation - WoS: 36Citation - Scopus: 36Selective Remanent Ambipolar Charge Transport in Polymeric Field-Effect Transistors for High-Performance Logic Circuits Fabricated in Ambient(Wiley-VCH Verlag GmbH, 2014-10-06) Fabiano, Simone; Usta, Hakan; Forchheimer, Robert; Crispin, Xavier; Facchetti, Antonio; Berggren, MagnusArticle Citation - WoS: 11Citation - Scopus: 12Optical Gain in Ultrathin Self-Assembled Bi-Layers of Colloidal Quantum Wells Enabled by the Mode Confinement in Their High-Index Dielectric Waveguides(Wiley-VCH Verlag GmbH, 2020-10-20) Foroutan-Barenji, Sina; Erdem, Onur; Gheshlaghi, Negar; Altintas, Yemliha; Demir, Hilmi VolkanThis study demonstrates an ultra-thin colloidal gain medium consisting of bi-layers of colloidal quantum wells (CQWs) with a total film thickness of 14 nm integrated with high-index dielectrics. To achieve optical gain from such an ultra-thin nanocrystal film, hybrid waveguide structures partly composed of self-assembled layers of CQWs and partly high-index dielectric material are developed and shown: in asymmetric waveguide architecture employing one thin film of dielectric underneath CQWs and in the case of quasi-symmetric waveguide with a pair of dielectric films sandwiching CQWs. Numerical modeling indicates that the modal confinement factor of ultra-thin CQW films is enhanced in the presence of the adjacent dielectric layers significantly. The active slabs of these CQW monolayers in the proposed waveguide structure are constructed with great care to obtain near-unity surface coverage, which increases the density of active particles, and to reduce the surface roughness to sub-nm scale, which decreases the scattering losses. The excitation and propagation of amplified spontaneous emission (ASE) along these active waveguides are experimentally demonstrated and numerically analyzed. The findings of this work offer possibilities for the realization of ultra-thin electrically driven colloidal laser devices, providing critical advantages including single-mode lasing and high electrical conduction.Article Citation - WoS: 88Citation - Scopus: 85Highly Stable, Near-Unity Efficiency Atomically Flat Semiconductor Nanocrystals of CdSe/ZnS Hetero-Nanoplatelets Enabled by ZnS-Shell Hot-Injection Growth(Wiley-VCH Verlag GmbH, 2019-01-30) Altintas, Yemliha; Quliyeva, Ulviyya; Gungor, Kivanc; Erdem, Onur; Kelestemur, Yusuf; Mutlugun, Evren; Demir, Hilmi VolkanColloidal semiconductor nanoplatelets (NPLs) offer important benefits in nanocrystal optoelectronics with their unique excitonic properties. For NPLs, colloidal atomic layer deposition (c-ALD) provides the ability to produce their core/shell heterostructures. However, as c-ALD takes place at room temperature, this technique allows for only limited stability and low quantum yield. Here, highly stable, near-unity efficiency CdSe/ZnS NPLs are shown using hot-injection (HI) shell growth performed at 573 K, enabling routinely reproducible quantum yields up to 98%. These CdSe/ZnS HI-shell hetero-NPLs fully recover their initial photoluminescence (PL) intensity in solution after a heating cycle from 300 to 525 K under inert gas atmosphere, and their solid films exhibit 100% recovery of their initial PL intensity after a heating cycle up to 400 K under ambient atmosphere, by far outperforming the control group of c-ALD shell-coated CdSe/ZnS NPLs, which can sustain only 20% of their PL. In optical gain measurements, these core/HI-shell NPLs exhibit ultralow gain thresholds reaching approximate to 7 mu J cm(-2). Despite being annealed at 500 K, these ZnS-HI-shell NPLs possess low gain thresholds as small as 25 mu J cm(-2). These findings indicate that the proposed 573 K HI-shell-grown CdSe/ZnS NPLs hold great promise for extraordinarily high performance in nanocrystal optoelectronics.Article Citation - WoS: 45Citation - Scopus: 46Exploring CsPbx3 (X = Cl, Br, I) Perovskite Nanocrystals in Amorphous Oxide Glasses: Innovations in Fabrication and Applications(Wiley-VCH Verlag GmbH, 2023-12-10) Samiei, Sadaf; Soheyli, Ehsan; Vighnesh, Kunnathodi; Nabiyouni, Gholamreza; Rogach, Andrey L.Metal halide perovskites with excellent optical and electronic properties have become a trending material in the current research. However, their limited stability under ambient conditions degrades quality and threatens their potential commercialization as optoelectronic devices. Various approaches are adopted to improve the stability of perovskite nanocrystals (PeNC) while maintaining their advantageous optical properties, particularly strong luminescence. Among different possible improvement strategies, encapsulation of PeNCs within the amorphous glass matrices of inorganic oxides has drawn widespread attention because it ensures high resistance against chemical corrosion and high temperature, thus enhancing their chemical, thermal, and mechanical stability with improved light-emission characteristics. In this article, two types of materials, namely all-inorganic metal halide PeNCs and amorphous oxide glasses are briefly introduced, and then the methods are reviewed to fabricate and improve the quality of PeNC@glass composites. These methods are classified into three universal categories: compositional modification, structural modification, and dual encapsulation. In the final part of this review paper, examples of applications of PeNCs@glass composites in light-emitting devices and displays, data storage and anti-counterfeiting, lasing, photodetectors and X-ray detectors, photocatalysis, optical filters, solar concentrators, and batteries are provided.