Now showing items 1-20 of 69

    • 1.3 μm GaAs based resonant cavity enhanced Schottky barrier internal photoemission photodetector 

      Necmi, B.; Kimukin, I.; Özbay, Ekmel; Tuttle, G. (IEEE, Piscataway, NJ, United States, 2000)
      GaAs based photodetectors operating at 1.3 μm that depend on internal photoemission as the absorption mechanism were fabricated. Quantum efficiency (QE) was increased using resonant cavity enhancement (RCE) effect.
    • 100-GHz resonant cavity enhanced Schottky photodiodes 

      Onat, B. M.; Gökkavas, M.; Özbay, Ekmel; Ata, E. P.; Towe, E.; Ünlü, M. S. (Institute of Electrical and Electronics Engineers, 1998)
      Resonant cavity enhanced (RCE) photodiodes are promising candidates for applications in optical communications and interconnects where ultrafast high-efficiency detection is desirable. We have designed and fabricated RCE ...
    • 45 GHz bandwidth-efficiency resonant cavity enhanced ITO-Schottky photodiodes 

      Bıyıklı, Necmi; Kimukin, İbrahim; Aytür, Orhan; Özbay, Ekmel; Gökkavas, M.; Ünlü, M. S. (OSA, 2001)
      We demonstrated high-performance resonant cavity enhanced ITO-Schottky photodiodes. We achieved a peak efficiency of 75% around 820 nm with a 3-dB bandwidth of 60 GHz resulting in a bandwidth-efficiency product of 45 GHz.
    • 45-GHz bandwidth-efficiency resonant-cavity-enhanced ITO-Schottky photodiodes 

      Bıyıklı, Necmi; Kimukin, I.; Aytür, O.; Gökkavas, M.; Ünlü, M. S.; Özbay, Ekmel (IEEE, 2001)
      High-speed Schottky photodiodes suffer from low efficiency mainly due to the thin absorption layers and the semitransparent Schottky-contact metals. We have designed, fabricated and characterized high-speed and high-efficiency ...
    • AlGaN quadruple-band photodetectors 

      Gökkavas, Mutlu; Bütün, Serkan; Caban, P.; Strupinski, W.; Özbay, Ekmel (IEEE, 2009)
      Quadruple back-illuminated ultraviolet metal-semiconductor-metal photodetectors with four different spectral responsivity bands were demonstrated. The average of the full-width at half-maximum (FWHM) of the quantum efficiency ...
    • AlxGa1-xN-based avalanche photodiodes with high reproducible avalanche gain 

      Tut, Turgut; Gökkavas, Mutlu; Özbay, Ekmel (2008)
      We report high performance solar-blind photodetectors with reproducible avalanche gain as high as 1570 under ultraviolet illumination. The solar-blind photodetectors have a sharp cut-off around 276 nm. The dark currents ...
    • Atomic layer deposited Al 2O 3 passivation of type II InAs/GaSb superlattice photodetectors 

      Salihoğlu, Ömer; Muti, Abdullah; Kutluer, Kutlu; Tansel, T.; Turan, R.; Kocabaş, Coşkun; Aydınlı, Atilla (AIP, 2012)
      Taking advantage of the favorable Gibbs free energies, atomic layer deposited (ALD) aluminum oxide (Al 2O 3) was used as a novel approach for passivation of type II InAs/GaSb superlattice (SL) midwave infrared (MWIR) single ...
    • Au/TiO2 nanorod-based Schottky-type UV photodetectors 

      Karaagac, H.; Aygun, L. E.; Parlak, M.; Ghaffari, M.; Bıyıklı, Necmi; Okyay, Ali Kemal (Wiley, 2012-10-12)
      TiO2 nanorods (NRs) were synthesized on fluorine-doped tin oxide (FTO) pre-coated glass substrates using hydrothermal growth technique. Scanning electron microscopy studies have revealed the formation of vertically-aligned ...
    • CdSe/ZnS core-shell nanocrystal based scintillators for enhanced detection in UV 

      Demir, Hilmi Volkan; Soğancı, İbrahim Murat; Mutlugün, Evren (IEEE, 2006)
      In this work, we present a novel scintillator that incorporates CdSe/ZnS core-shell nanocrystals to utilize both their high quantum fluorescence efficiency in the visible and high optical absorption in the UV for the purpose ...
    • Dark current reduction in ultraviolet metal-semiconductor-metal photodetectors based on wide band-gap semiconductors 

      Bütün, Serkan; Gökkavas, Mutlu; Yu, HongBo; Strupinski, Vlodek; Özbay, Ekmel (IEEE, 2009-10)
      Photodetectors on semi-insulating GaN templates were demonstrated. They exhibit lower dark current compared to photodetectors fabricated on regular GaN templates. Similar behavior observed in photodetectors fabricated on ...
    • Deep-ultraviolet Al0.75Ga0.25N photodiodes with low cutoff wavelength 

      Bütün, S.; Tut, T.; Bütün, B.; Gökkavas, M.; Yu, H.; Özbay, Ekmel (AIP Publishing LLC, 2006-03-21)
      Deep ultraviolet Al0.75Ga0.25N metal-semiconductor-metal photodetectors with high Al concentration have been demonstrated. A metal-organic chemical vapor deposition grown high quality Al0.75Ga0.25N layer was used as a ...
    • Design and optimization of high-speed resonant cavity enhanced Schottky photodiodes 

      Gökkavas, M.; Onat, B. M.; Özbay, Ekmel; Ata, E. P.; Xu, J.; Towe, E.; Ünlü, M. S. (Institute of Electrical and Electronics Engineers, 1999-02)
      Resonant cavity enhanced (RCE) photodiodes (PD's) are promising candidates for applications in optical communications and interconnects where high-speed high-efficiency photodetection is desirable. In RCE structures, the ...
    • Design, fabrication and characterization of high-performance solarblind AlGaN photodetectors 

      Özbay, Ekmel (SPIE, 2005)
      Design, fabrication, and characterization of high-performance AlxGal-xN-based photodetectors for solar-blind applications are reported. AlxGal-xN heterostructures were designed for Schottky, p-i-n, and metal-semiconductor-metal ...
    • Dual-color ultraviolet metal-semiconductor-metal AlGaN photodetectors 

      Gökkavas, M.; Bütün, S.; Yu, H.; Tut, T.; Bütün, B.; Özbay, Ekmel (AIP Publishing LLC, 2006)
      Backilluminated ultraviolet metal-semiconductor-metal photodetectors with different spectral responsivity bands were demonstrated on a single Alx Ga1-x N heterostructure. This was accomplished by the incorporation of an ...
    • Electrical performance of InAs/AlSb/GaSb superlattice photodetectors 

      Tansel, T.; Hostut M.; Elagoz, S.; Kilic A.; Ergun, Y.; Aydınlı, Atilla (Academic Press, 2016)
      Temperature dependence of dark current measurements is an efficient way to verify the quality of an infrared detector. Low dark current density values are needed for high performance detector applications. Identification ...
    • Electronic and optical properties of 4.2 μm"N" structured superlattice MWIR photodetectors 

      Salihoglu, O.; Hostut M.; Tansel, T.; Kutluer, K.; Kilic A.; Alyoruk, M.; Sevik, C.; Turan, R.; Ergun, Y.; Aydınlı, Atilla (Elsevier, 2013)
      We report on the development of a new structure for type II superlattice photodiodes that we call the "N" design. In this new design, we insert an electron barrier between InAs and GaSb in the growth direction. The barrier ...
    • Fabrication of high-speed resonant cavity enhanced schottky photodiodes 

      Özbay, Ekmel; Islam, M. S.; Onat, B.; Gökkavas, M.; Aytür, O.; Tuttle, G.; Towe, E.; Henderson, R. H.; Ünlü, M. S. (Institute of Electrical and Electronics Engineers, 1997-05)
      We report the fabrication and testing of a GaAs-based high-speed resonant cavity enhanced (RCE) Schottky photodiode. The top-illuminated RCE detector is constructed by integrating a Schottky contact, a thin absorption ...
    • GaN/AlGaN-based UV photodetectors with performances exceeding the PMTS 

      Tut, Turgut (Bilkent University, 2008)
      The recent developments in high Al-content AlxGa1−xN material growth technology made it possible to fabricate high performance solar-blind photodetectors operating in the ultraviolet (UV) spectral region with improved receiver ...
    • High efficiency monolithic photodetectors for integrated optoelectronics in the near infrared 

      Okyay, Ali Kemal; Onbaşlı, M. Cengiz; Ercan, Burcu; Yu H.-Y.; Ren, S.; Miller, D.A.B.; Saraswat, K.C.; Nayfeh, A.M. (IEEE, 2009)
      Monolithic Germanium photodetectors integrated on Si with external efficiency up to 68% at 1550nm and low dark current density 3.2mA/cm2 are demonstrated. The absorption edge red shifted by 47nm corresponding to bandgap ...
    • High performance infrared photodetectors up to 2.8 μm wavelength based on lead selenide colloidal quantum dots 

      Thambidurai, M.; Jang, Y.; Shapiro, A.; Yuan, G.; Xiaonan, H.; Xuechao, Y.; Wang, Q. J.; Lifshitz, E.; Demir, Hilmi Volkan; Dang C. (OSA - The Optical Society, 2017)
      The strong quantum confinement effect in lead selenide (PbSe) colloidal quantum dots (CQDs) allows to tune the bandgap of the material, covering a large spectral range from mid- to near infrared (NIR). Together with the ...