Browsing by Author "Polat, E. O."

Now showing items 1-12 of 12

    • Broadband optical modulators based on graphene supercapacitors 

      Polat, E. O.; Kocabas, C. (American Chemical Society, 2013)
      Optical modulators are commonly used in communication and information technology to control intensity, phase, or polarization of light. Electro-optic, electroabsorption, and acousto-optic modulators based on semiconductors ...

    • Broadband terahertz modulators using self-gated graphene capacitors 

      Kakenov, N.; Balci, O.; Polat, E. O.; Altan, H.; Kocabas, C. (Optical Society of America, 2015)
      We demonstrate a terahertz intensity modulator using a graphene supercapacitor which consists of two large-area graphene electrodes and an electrolyte medium. The mutual electrolyte gating between the graphene electrodes ...

    • Electrically switchable metadevices via graphene 

      Balcı, Osman; Kakenov, Nurbek; Karademir, E.; Balcı, S.; Çakmakyapan, S.; Polat, E. O.; Cağlayan, H.; Özbay, Ekmel; Kocabaş, Coşkun (American Association for the Advancement of Science, 2018)
      Metamaterials bring subwavelength resonating structures together to overcome the limitations of conventional materials. The realization of active metadevices has been an outstanding challenge that requires electrically ...

    • Femtosecond pulse generation with voltage-controlled graphene saturable absorber 

      Baylam, M. N.; Cizmeciyan, S.; Ozharar, S.; Polat, E. O.; Kocabas, C.; Sennaroglu, A. (Optical Society of America, 2014)
      We report, for the first time to our knowledge, the demonstration of a graphene supercapacitor as a voltage-controlled saturable absorber for femtosecond pulse generation from a solid-state laser. By applying only a few ...

    • Gate-tunable photoemission from graphene transistors 

      Copuroglu, M.; Aydogan, P.; Polat, E. O.; Kocabas, C.; Süzer, S. (American Chemical Society, 2014)
      In this Letter, we report gate-tunable X-ray photoelectron emission from back-gated graphene transistors. The back-gated transistor geometry allows us to study photoemission from graphene layer and the dielectric substrate ...

    • Graphene based flexible electrochromic devices 

      Polat, E. O.; Balci, O.; Kocabas, C. (Nature Publishing Group, 2014-10-01)
      Graphene emerges as a viable material for optoelectronics because of its broad optical response and gate-tunable properties. For practical applications, however, single layer graphene has performance limits due to its small ...

    • Graphene-enabled electrically controlled terahertz spatial light modulators 

      Kakenov, N.; Takan, T.; Ozkan, V. A.; Balcı, O.; Polat, E. O.; Altan, H.; Kocabas, C. (Optical Society of America, 2015-05-01)
      In this Letter, we demonstrate a broadband terahertz (THz) spatial light modulator using 5×5 arrays of large area graphene supercapacitors. Our approach relies on controlling spatial charge distribution on a passive matrix ...

    • Graphene-enabled optoelectronics on paper 

      Polat, E. O.; Uzlu, H. B.; Balci, O.; Kakenov, N.; Kovalska, E.; Kocabas, C. (American Chemical Society, 2016-06)
      The realization of optoelectronic devices on paper has been an outstanding challenge due to the large surface roughness and incompatible nature of paper with optical materials. Here, we demonstrate a new class of optoelectronic ...

    • Highly proton conductive phosphoric acid-nonionic surfactant lyotropic liquid crystalline mesophases and application in graphene optical modulators 

      Tunkara, E.; Albayrak, C.; Polat, E. O.; Kocabas, C.; Dag, Ö. (American Chemical Society, 2014)
      Proton conducting gel electrolytes are very important components of clean energy devices. Phosphoric acid (PA, H3PO4 3 H2O) is one of the best proton conductors, but needs to be incorporated into some matrix for real ...

    • Synthesis of graphene on gold 

      Oznuluer, T.; Pince, E.; Polat, E. O.; Balci, O.; Salihoglu, O.; Kocabas, C. (A I P Publishing, 2011)
      Here we report chemical vapor deposition of graphene on gold surface at ambient pressure. We studied effects of the growth temperature, pressure, and cooling process on the grown graphene layers. The Raman spectroscopy of ...

    • Synthesis of graphene on ultra-smooth copper foils for large area flexible electronics 

      Polat, E. O.; Balcı, Osman; Kakenov, Nurbek; Kocabaş, Coşkun; Dahiya, R. (IEEE, 2015)
      This work demonstrates the synthesis of high quality, single layer graphene on commercially available ultra-smooth copper foils. The presented method will result in improved scalability of graphene based electronic and ...

    • X-ray photoelectron spectroscopy for identification of morphological defects and disorders in graphene devices 

      Aydogan, P.; Polat, E. O.; Kocabas, C.; Süzer, Şefik (AIP Publishing, 2016)
      The progress in the development of graphene devices is promising, and they are now considered as an option for the current Si-based electronics. However, the structural defects in graphene may strongly influence the local ...