Browsing by Author "Erdem, Onur"

Now showing items 1-20 of 23

    • Anomalous spectral characteristics of ultrathin sub-nm colloidal CdSe nanoplatelets 

      Bose S.; Delikanlı, Savaş; Yeltik, Aydan; Sharma, Manoj; Erdem, Onur; Dang C.; Fan W.; Zhang D.H.; Demir, Hilmi Volkan (Optical Society of America, 2017)
      We demonstrate high quantum yield broad photoluminescence emission of ultrathin sub-nanometer CdSe nanoplatelets (two-monolayer). They also exhibit polarization-characterized lateral size dependent anomalous heavy hole and ...

    • Cd-free Cu-doped ZnInS/ZnS Core/Shell nanocrystals: Controlled synthesis and photophysical properties 

      Kaur, Manpreet; Sharma, Ashma; Olutaş, Murat; Erdem, Onur; Kumar, A.; Sharma, Manoj; Demir, Hilmi Volkan (SpringerOpen, 2018)
      Here, we report efficient composition-tunable Cu-doped ZnInS/ZnS (core and core/shell) colloidal nanocrystals (CNCs) synthesized by using a colloidal non-injection method. The initial precursors for the synthesis were used ...

    • Colloidal optoelectronics of self-assembled quantum well superstructures 

      Erdem, Onur (Bilkent University, 2020-06)
      Advances in the colloidal nanocrystal synthesis enabled creation of quasi twodimensional colloidal quantum wells (CQWs) in the last decade. These CQWs possess similar properties to those of epitaxially grown quantum wells ...

    • Colloidal semiconductor nanocrystals 

      Erdem, Onur; Demir, Hilmi Volkan (Springer Singapore, 2022-10-28)
      In this chapter, we review colloidal semiconductor nanocrystals (NCs) and their remarkable size-dependent properties. We emphasize on colloidal nanoplatelets and explain how they differ from NCs of other classes.

    • Conclusions and future outlook 

      Erdem, Onur; Demir, Hilmi Volkan (Springer Singapore, 2022-10-28)

    • Highly stable, near-unity efficiency atomically flat semiconductor nanocrystals of CdSe/ZnS hetero-nanoplatelets enabled by ZnS-Shell hot-injection growth 

      Yemliha, Yemliha; Quliyeva, Ulviyya; Güngör, Kıvanç; Erdem, Onur; Kelestemur, Yusuf; Mutlugün, Evren; Kovalenko, M.; Demir, Hilmi Volkan (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2019)
      Colloidal 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 ...

    • Introduction 

      Erdem, Onur; Demir, Hilmi Volkan (Springer Singapore, 2022-10-28)
      We begin by giving a short overview of colloidal nanoplatelets, and we explain why their orientation-controlled assemblies are of particular interest. We finalize the chapter by giving an outline of our brief.

    • Light-induced paramagnetism in colloidal Ag+-doped CdSe nanoplatelets 

      Najafi, A.; Sharma, Manoj; Delikanlı, Savaş; Bhattacharya, A.; Murphy, J. R.; Pientka, J.; Sharma, A.; Quinn, A. P.; Erdem, Onur; Kattel, S.; Kelestemur, Y.; Kovalenko, M. V.; Rice, W. D.; Demir, Hilmi Volkan; Petrou, A. (American Chemical Society, 2021-03-25)
      We describe a study of the magneto-optical properties of Ag+-doped CdSe colloidal nanoplatelets (NPLs) that were grown using a novel doping technique. In this work, we used magnetic circularly polarized luminescence and ...

    • Liquid interface self-assembly of colloidal nanoplatelets for optoelectronics 

      Erdem, Onur; Demir, Hilmi Volkan (Springer Singapore, 2022-10-28)
      In this chapter, we discuss how liquid interface self-assembly can contribute to the utilization of colloidal semiconductor nanoplatelets in optoelectronics. Self-assembled nanoplatelet mono- or multilayers can be used as ...

    • Liquid interface self-assembly with colloidal quantum wells 

      Erdem, Onur; Demir, Hilmi Volkan (Springer Singapore, 2022-10-28)
      In this chapter, we discuss our methodologies for the self-assembly of colloidal nanoplatelets (NPLs) at the liquid interface. We also review other recent studies on orientation-controlled platelet assembly on liquid ...

    • Mechanosynthesis of polymer-stabilized lead bromide perovskites: insight into the formation and phase conversion of nanoparticles 

      Jiang, G.; Erdem, Onur; Hübner, R.; Georgi, M.; Wei, W.; Fan, X.; Wang, J.; Demir, Hilmi Volkan (Tsinghua University Press, 2021-04)
      The application of polymers to replace oleylamine (OLA) and oleic acid (OA) as ligands for perovskite nanocrystals is an effective strategy to improve their stability and durability especially for the solution-based ...

    • Near-field energy transfer into silicon inversely proportional to distance using quasi-2D colloidal quantum well donors 

      Humayun, Muhammad Hamza; Hernandez-Martinez, Pedro Ludwig; Gheshlaghi, Negar; Erdem, Onur; Altıntaş, Yemliha; Shabani, Farzan; Demir, Hilmi Volkan (Wiley-VCH Verlag GmbH & Co. KGaA, 2021-09-12)
      Silicon is the most prevalent material system for light-harvesting applications; however, its inherent indirect bandgap and consequent weak absorption limits its potential in optoelectronics. This paper proposes to address ...

    • Observation of optical gain from aqueous quantum well heterostructures in water 

      Delikanlı, Savaş; Durmuşoğlu, E.G.; Erdem, Onur; Shabani, Farzan; Kumar, Satish; Barujb, Hamed Dehghanpour; Demir, Hilmi Volkan; Işık, Furkan; Canımkurbey, Betül (Royal Society of Chemistry, 2022-09-25)
      Although achieving optical gain using aqueous solutions of colloidal nanocrystals as a gain medium is exceptionally beneficial for bio-optoelectronic applications, the realization of optical gain in an aqueous medium using ...

    • Optical gain in ultrathin self‐assembled bi‐layers of colloidal quantum wells enabled by the mode confinement in their high‐index dielectric waveguides 

      Foroutan-Barenji, Sina; Erdem, Onur; Gheshlaghi, Negar; Altıntaş, Yemliha; Demir, Hilmi Volkan (Wiley-VCH Verlag, 2020)
      This 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 ...

    • Orientation-controlled nonradiative energy transfer to colloidal nanoplatelets: engineering dipole orientation factor 

      Erdem, Onur; Güngör, Kıvanç; Güzeltürk, Burak; Tanrıöver, İbrahim; Sak, Mustafa; Olutaş, Murat; Dede, Didem; Kelestemur, Yusuf; Demir, Hilmi Volkan (American Chemical Society, 2019)
      We proposed and showed strongly orientation-controlled Förster resonance energy transfer (FRET) to highly anisotropic CdSe nanoplatelets (NPLs). For this purpose, we developed a liquid–air interface self-assembly technique ...

    • Self-assembly of colloidal nanocrystals 

      Erdem, Onur; Demir, Hilmi Volkan (Springer Singapore, 2022-10-28)
      We describe different approaches to colloidal nanocrystal self-assembly and review the reports where different NC superstructures were constructed using these techniques.

    • Self-resonant microlasers of colloidal quantum wells constructed by direct deep patterning 

      Gheshlaghi, Negar; Foroutan-Barenji, Sina; Erdem, Onur; Altintas, Yemliha; Shabani, Farzan; Humayun, Muhammad Hamza; Demir, Hilmi Volkan (American Chemical Society, 2021-06-09)
      Here, the first account of self-resonant fully colloidal μ-lasers made from colloidal quantum well (CQW) solution is reported. A deep patterning technique is developed to fabricate well-defined high aspect-ratio on-chip ...

    • Single-mode lasing from a single 7 nm thick monolayer of colloidal quantum wells in a monolithic microcavity 

      Foroutan-Barenji, Sina; Erdem, Onur; Delikanlı, Savaş; Yağcı, Hüseyin Bilge; Gheshlaghi, Negar; Altıntaş, Yemliha; Demir, Hilmi Volkan (Wiley-VCH Verlag, 2021-03-03)
      In this work, monolithically-fabricated vertical cavity surface emitting lasers (VCSELs) of densely-packed, orientation-controlled, atomically flat colloidal quantum wells (CQWs) using a self-assembly method is reported ...

    • Thickness-tunable self-assembled colloidal nanoplatelet films enable ultrathin optical gain media 

      Erdem, Onur; Foroutan, Sina; Gheshlaghi, Negar; Güzeltürk, B.; Altıntaş, Yemliha; Demir, Hilmi Volkan (American Chemical Society, 2020)
      We propose and demonstrate construction of highly uniform, multilayered superstructures of CdSe/CdZnS core/shell colloidal nanoplatelets (NPLs) using liquid interface self-assembly. These NPLs are sequentially deposited ...

    • Ultrahigh green and red optical gain cross sections from solutions of colloidal quantum well heterostructures 

      Delikanli, Savaş; Erdem, Onur; Işık, Furkan; Dehghanpour Baruj, Hamed; Shabani, Farzan; Yağcı, Hüseyin Bilge; Durmuşoğlu, E. G.; Demir, Hilmi Volkan (American Chemical Society, 2021-03-11)
      We demonstrate amplified spontaneous emission (ASE) in solution with ultralow thresholds of 30 μJ/cm2 in red and of 44 μJ/cm2 in green from engineered colloidal quantum well (CQW) heterostructures. For this purpose, CdSe/CdS ...