Metasurface integrated high energy efficient and high linearly polarized InGaN/GaN light emitting diode.

We proposed and demonstrated an integrated high energy efficient and high linearly polarized InGaN/GaN green LED grown on (0001) oriented sapphire with combined metasurface polarizing converter and polarizer system. It is different from those conventional polarized light emissions generated with plasmonic metallic grating in which at least 50% high energy loss occurs inherently due to high reflection of the transverse electric (TE) component of an electric field. A reflecting metasurface, with a two dimensional elliptic metal cylinder array (EMCA) that functions as a half-wave plate, was integrated at the bottom of a LED such that the back-reflected TE component, that is otherwise lost by a dielectric/metal bi-layered wire grids (DMBiWG) polarizer on the top emitting surface of the LED, can be converted to desired transverse magnetic (TM) polarized emission after reflecting from the metasurface. This significantly enhances the polarized light emission efficiency. Experimental results show that extraction efficiency of the polarized emission can be increased by 40% on average in a wide angle of ±60° compared to that with the naked bottom of sapphire substrate, or 20% compared to reflecting Al film on the bottom of a sapphire substrate. An extinction ratio (ER) of average value 20 dB within an angle of ±60° can be simultaneously obtained directly from an InGaN/GaN LED. Our results show the possibility of simultaneously achieving a high degree of polarization and high polarization extraction efficiency at the integrated device level. This advances the field of GaN LED toward energy efficiency, multi-functional applications in illumination, display, medicine, and light manipulation.

[1]  Ji Ma,et al.  Structure and application of polarizer film for thin-film-transistor liquid crystal displays , 2011, Displays.

[2]  Morten Willatzen,et al.  Plasmonic metamaterial wave retarders in reflection by orthogonally oriented detuned electrical dipoles. , 2011, Optics letters.

[3]  Stefan Linden,et al.  Polarization Stop Bands in Chiral Polymeric Three‐Dimensional Photonic Crystals , 2007 .

[4]  James S. Speck,et al.  High-brightness polarized light-emitting diodes , 2012, Light: Science & Applications.

[5]  Zhong Lin Wang,et al.  Simultaneously Enhancing Light Emission and Suppressing Efficiency Droop in GaN Microwire-Based Ultraviolet Light-Emitting Diode by the Piezo-Phototronic Effect. , 2017, Nano letters.

[6]  Cees W. M. Bastiaansen,et al.  Linearly polarized light‐emitting backlight , 2002 .

[7]  Ke Xu,et al.  High linearly polarized light emission from InGaN light-emitting diode with multilayer dielectric/metal wire-grid structure , 2014 .

[8]  M. Wegener,et al.  Gold Helix Photonic Metamaterial as Broadband Circular Polarizer , 2009, Science.

[9]  Tao Wang,et al.  Enhanced polarization of (11–22) semi-polar InGaN nanorod array structure , 2015 .

[10]  J. Valentine,et al.  Dielectric meta-reflectarray for broadband linear polarization conversion and optical vortex generation. , 2014, Nano letters.

[11]  Hiroaki Ohta,et al.  Characteristics of Polarized Electroluminescence from m-plane InGaN-based Light Emitting Diodes , 2007 .

[12]  James S. Speck,et al.  Prospects for LED lighting , 2009 .

[13]  N. Yu,et al.  A broadband, background-free quarter-wave plate based on plasmonic metasurfaces. , 2012, Nano letters.

[14]  Semiconductor lasers with integrated plasmonic polarizers , 2009 .

[15]  Nan Zeng,et al.  Linear polarization different imaging and its potential applications , 2008, 2008 Asia Optical Fiber Communication & Optoelectronic Exposition & Conference.

[16]  Andrea Alù,et al.  Tailoring the dispersion of plasmonic nanorods to realize broadband optical meta-waveplates. , 2013, Nano letters.

[17]  Hsuen‐Li Chen,et al.  Using nanoimprint lithography to improve the light extraction efficiency and color rendering of dichromatic white light-emitting diodes. , 2015, Nanoscale.

[18]  Masashi Kubota,et al.  Temperature dependence of polarized photoluminescence from nonpolar m-plane InGaN multiple quantum wells for blue laser diodes , 2008 .

[19]  E Fred Schubert,et al.  Linearly polarized emission from GaInN lightemitting diodes with polarization-enhancing reflector. , 2007, Optics express.

[20]  Wolfgang Schnick,et al.  A revolution in lighting. , 2015, Nature materials.

[21]  N. Kotov.  Sustainability of the academic enterprise in the United States. , 2015, ACS nano.

[22]  P. Sciortino,et al.  High-performance, large area, deep ultraviolet to infrared polarizers based on 40 nm line/78 nm space nanowire grids , 2007 .

[23]  Hao-Chung Kuo,et al.  Polarized light emission from photonic crystal light-emitting diodes , 2008 .

[24]  Broadband circular polarizers constructed using helix-like chiral metamaterials. , 2016, Nanoscale.

[25]  N I Zheludev,et al.  Giant gyrotropy due to electromagnetic-field coupling in a bilayered chiral structure. , 2006, Physical review letters.

[26]  Hong Seok Lee,et al.  Light-extraction enhancement of a GaN-based LED covered with ZnO nanorod arrays. , 2014, Nanoscale.

[27]  C. David,et al.  Bilayer Al wire-grids as broadband and high-performance polarizers. , 2006, Optics express.

[28]  Jonathan J. Wierer,et al.  Polarization anisotropy in the electroluminescence of m-plane InGaN–GaN multiple-quantum-well light-emitting diodes , 2005 .

[29]  Q. Wei,et al.  Polarization Conversion with Elliptical Patch Nanoantennas , 2012 .

[30]  James S. Speck,et al.  Polarized spontaneous emission from blue-green m-plane GaN-based light emitting diodes , 2011 .

[31]  Gordon W. Day,et al.  Stability of birefringent linear retarders (waveplates). , 1988, Applied optics.