Zongfu Yu

Summary

Affiliation: Stanford University
Country: USA

Publications

  1. pmc Fundamental limit of nanophotonic light trapping in solar cells
    Zongfu Yu
    Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA
    Proc Natl Acad Sci U S A 107:17491-6. 2010
  2. doi request reprint Absorption enhancement in ultrathin crystalline silicon solar cells with antireflection and light-trapping nanocone gratings
    Ken Xingze Wang
    Department of Applied Physics, Stanford University, Stanford, California 94305, USA
    Nano Lett 12:1616-9. 2012
  3. doi request reprint Optical absorption enhancement in amorphous silicon nanowire and nanocone arrays
    Jia Zhu
    Department of Electrical Engineering, Department of Applied Physics, Department of Materials Science and Engineering, and Department of Chemistry, Stanford University, Stanford, California 94305, USA
    Nano Lett 9:279-82. 2009
  4. doi request reprint A transparent electrode based on a metal nanotrough network
    Hui Wu
    Department of Materials Science and Engineering, Stanford University, California 94305, USA
    Nat Nanotechnol 8:421-5. 2013
  5. doi request reprint Hybrid silicon nanocone-polymer solar cells
    Sangmoo Jeong
    Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
    Nano Lett 12:2971-6. 2012
  6. doi request reprint Two-dimensional chalcogenide nanoplates as tunable metamaterials via chemical intercalation
    Judy J Cha
    Department of Materials Science and Engineering, Department of Electrical Engineering, Department of Applied Physics, and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, United States
    Nano Lett 13:5913-8. 2013
  7. doi request reprint Dielectric nanostructures for broadband light trapping in organic solar cells
    Aaswath Raman
    Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
    Opt Express 19:19015-26. 2011
  8. ncbi request reprint From electromagnetically induced transparency to superscattering with a single structure: a coupled-mode theory for doubly resonant structures
    Lieven Verslegers
    Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
    Phys Rev Lett 108:083902. 2012
  9. doi request reprint Photonic de Haas-van Alphen effect
    Kejie Fang
    Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
    Opt Express 21:18216-24. 2013
  10. doi request reprint Fundamental bounds on decay rates in asymmetric single-mode optical resonators
    Ken Xingze Wang
    Department of Applied Physics, Stanford University, Stanford, California 94305, USA
    Opt Lett 38:100-2. 2013

Collaborators

Detail Information

Publications23

  1. pmc Fundamental limit of nanophotonic light trapping in solar cells
    Zongfu Yu
    Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA
    Proc Natl Acad Sci U S A 107:17491-6. 2010
    ..Our theory reveals that the conventional limit can be substantially surpassed when optical modes exhibit deep-subwavelength-scale field confinement, opening new avenues for highly efficient next-generation solar cells...
  2. doi request reprint Absorption enhancement in ultrathin crystalline silicon solar cells with antireflection and light-trapping nanocone gratings
    Ken Xingze Wang
    Department of Applied Physics, Stanford University, Stanford, California 94305, USA
    Nano Lett 12:1616-9. 2012
    ..6 mA/cm(2) at an equivalent thickness of 2 μm, close to the Yablonovitch limit. This approach is applicable to various thicknesses and is robust against metallic loss in the back reflector...
  3. doi request reprint Optical absorption enhancement in amorphous silicon nanowire and nanocone arrays
    Jia Zhu
    Department of Electrical Engineering, Department of Applied Physics, Department of Materials Science and Engineering, and Department of Chemistry, Stanford University, Stanford, California 94305, USA
    Nano Lett 9:279-82. 2009
    ..Our experimental data agree very well with simulation. The a-Si:H nanocones function as both absorber and antireflection layers, which offer a promising approach to enhance the solar cell energy conversion efficiency...
  4. doi request reprint A transparent electrode based on a metal nanotrough network
    Hui Wu
    Department of Materials Science and Engineering, Stanford University, California 94305, USA
    Nat Nanotechnol 8:421-5. 2013
    ..We demonstrate the practical suitability of our transparent conducting electrode by fabricating a flexible touch-screen device and a transparent conducting tape...
  5. doi request reprint Hybrid silicon nanocone-polymer solar cells
    Sangmoo Jeong
    Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
    Nano Lett 12:2971-6. 2012
    ..1 mA/cm(2), which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution...
  6. doi request reprint Two-dimensional chalcogenide nanoplates as tunable metamaterials via chemical intercalation
    Judy J Cha
    Department of Materials Science and Engineering, Department of Electrical Engineering, Department of Applied Physics, and Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, United States
    Nano Lett 13:5913-8. 2013
    ..We show that these modal properties can also be tuned effectively by more conventional methods such as thickness control and alloy composition of the nanoplates. ..
  7. doi request reprint Dielectric nanostructures for broadband light trapping in organic solar cells
    Aaswath Raman
    Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
    Opt Express 19:19015-26. 2011
    ..The techniques developed here are broadly applicable to organic semiconductors in general, and enable partial decoupling between active layer thickness and photocurrent generation...
  8. ncbi request reprint From electromagnetically induced transparency to superscattering with a single structure: a coupled-mode theory for doubly resonant structures
    Lieven Verslegers
    Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
    Phys Rev Lett 108:083902. 2012
    ..These results provide insight in the general electromagnetic properties of photonic nanostructures and metamaterials...
  9. doi request reprint Photonic de Haas-van Alphen effect
    Kejie Fang
    Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
    Opt Express 21:18216-24. 2013
    ....
  10. doi request reprint Fundamental bounds on decay rates in asymmetric single-mode optical resonators
    Ken Xingze Wang
    Department of Applied Physics, Stanford University, Stanford, California 94305, USA
    Opt Lett 38:100-2. 2013
    ..The analytic predictions are verified against full-field electromagnetic simulations...
  11. doi request reprint Detailed balance analysis and enhancement of open-circuit voltage in single-nanowire solar cells
    Sunil Sandhu
    Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
    Nano Lett 14:1011-5. 2014
    ..In addition, we elucidate the physics of open-circuit voltage enhancement over bulk cells in nanowires, by showing that the enhancement is related to the removal of resonances in the immediate spectral vicinity above the bandgap. ..
  12. ncbi request reprint Optical Fano resonance of an individual semiconductor nanostructure
    Pengyu Fan
    Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
    Nat Mater 13:471-5. 2014
    ..Together they can provide a complete experimental characterization of this type of resonance. ..
  13. doi request reprint Efficiency above the Shockley-Queisser limit by using nanophotonic effects to create multiple effective bandgaps with a single semiconductor
    Zongfu Yu
    Department of Electrical Engineering and Ginzton Laboratory, Stanford University, Stanford, California 94305, United States
    Nano Lett 14:66-70. 2014
    ..In a tandem cell configuration constructed from a single material, one can achieve two different effective bandgaps, thereby exceeding the Shockley-Queisser limit. ..
  14. ncbi request reprint Thermodynamic upper bound on broadband light coupling with photonic structures
    Zongfu Yu
    Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
    Phys Rev Lett 109:173901. 2012
    ..Such bound limits how efficient light can be coupled to any photonic structure. As one example of application, we use this upper bound to derive the limit of light absorption in broadband solar absorbers...
  15. ncbi request reprint Photonic Aharonov-Bohm effect based on dynamic modulation
    Kejie Fang
    Department of Physics, Stanford University, Stanford, California 94305, USA
    Phys Rev Lett 108:153901. 2012
    ..This effective gauge potential can be used to create a photonic Aharonov-Bohm effect. We show that the photonic Aharonov-Bohm effect provides the optimal mechanism for achieving complete on-chip nonmagnetic optical isolation...
  16. ncbi request reprint Low reflectivity and high flexibility of tin-doped indium oxide nanofiber transparent electrodes
    Hui Wu
    Departments of Materials Science and Engineering and Electrical Engineering, Stanford University, Stanford, California 94305, United States
    J Am Chem Soc 133:27-9. 2011
    ..The nanofiber networks show optical reflectivity as low as 5% and high flexibility; the nanofiber networks can be bent to a radius of 2 mm with negligible changes in the sheet resistance...
  17. doi request reprint Detailed balance analysis of nanophotonic solar cells
    Sunil Sandhu
    Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA
    Opt Express 21:1209-17. 2013
    ..We also show that with proper design, the use of a grating on a nanoscale thin film can increase its short-circuit current, while preserving its voltage-enhancing capabilities...
  18. doi request reprint Enhancing far-field thermal emission with thermal extraction
    Zongfu Yu
    Department of Electrical Engineering and Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
    Nat Commun 4:1730. 2013
    ..As an experimental demonstration of the thermal extraction scheme, we observe a four-fold enhancement of the far-field thermal emission of a carbon-black emitter having an emissivity of 0.85...
  19. doi request reprint Combining radiationless interference with evanescent field amplification
    Varat Intaraprasonk
    Department of Applied Physics, Stanford University, Stanford, California 94305, USA
    Opt Lett 35:1659-61. 2010
    ..Our approach removes the exponential decay and, moreover, allows a much wider range of wave vectors, including both propagating and evanescent field components, to participate in the image-formation process...
  20. doi request reprint Extraordinarily high spectral sensitivity in refractive index sensors using multiple optical modes
    Zongfu Yu
    Ginzton Lab, Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
    Opt Express 19:10029-40. 2011
    ..We also show that there is a fundamental constraint between the spectral sensitivity and quality factor in such multi-mode sensing approach...
  21. doi request reprint Ultracompact nonreciprocal optical isolator based on guided resonance in a magneto-optical photonic crystal slab
    Kejie Fang
    Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305, USA
    Opt Lett 36:4254-6. 2011
    ..Our design utilizes guided resonance in a photonic crystal slab to enhance magneto-optical effects, and exploits interference effects among multiple resonances to create desired transmission spectral line shapes...
  22. ncbi request reprint Comment on "Nonreciprocal light propagation in a silicon photonic circuit"
    Shanhui Fan
    Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
    Science 335:38; author reply 38. 2012
    ..Moreover, one cannot construct an optical isolator by incorporating this structure into any system as long as the system is linear and time-independent and is described by materials with a scalar dielectric function...
  23. doi request reprint Planar lenses based on nanoscale slit arrays in a metallic film
    Lieven Verslegers
    E L Ginzton Laboratory, Geballe Laboratory for Advanced Materials GLAM, Stanford University, Stanford, California 94305, USA
    Nano Lett 9:235-8. 2009
    ..We find excellent agreement between electromagnetic simulations of the design and confocal measurements on manufactured structures. We provide guidelines for lens design and show how actual lens behavior deviates from simple theory...