Light emitting diodes including pedestals

Abstract

Light emitting diodes include a substrate having first and second opposing faces and that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face. A diode region on the second face is configured to emit light in the predetermined wavelength range, into the substrate upon application of voltage across the diode region. A mounting support on the diode region, opposite the substrate is configured to support the diode region, such that the light that is emitted from the diode region into the substrate, is emitted from the first face upon application of voltage across the diode region. The first face of the substrate may include therein a plurality of grooves that define the plurality of triangular pedestals in the substrate. The grooves may include tapered sidewalls and/or a beveled floor. The first face of the substrate also may include therein an array of via holes. The via holes may include tapered sidewalls and/or a floor.

1 . A light emitting diode comprising: 
 a substrate having first and second opposing faces, that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face; and    a diode region on the second face that is configured to emit light in the predetermined wavelength range into the substrate that is transparent to optical radiation in the predetermined wavelength range, upon application of voltage across the diode region.    
   
   
       2 . A light emitting diode according to  claim 1  further comprising: 
 a mounting support on the diode region, opposite the substrate that is transparent to optical radiation in the predetermined frequency range, the mounting support being configured to support the diode region such that the light that is emitted from the diode region into the substrate that is transparent to optical radiation in the predetermined wavelength range, is emitted from the plurality of pedestals, upon application of voltage across the diode region.    
   
   
       3 . A light emitting diode according to  claim 1  further comprising: 
 a mounting support on the first face, opposite the diode region, the mounting support being configured to support the first face.    
   
   
       4 . A light emitting diode according to  claim 2  further comprising: 
 a reflector between the mounting support and the diode region, that is configured to reflect light that is emitted from the diode region back into the diode region, through the substrate that is transparent to optical radiation in the predetermined wavelength range and from the plurality of pedestals, upon application of voltage across the diode region.    
   
   
       5 . A light emitting diode according to  claim 3  further comprising: 
 a reflector between the mounting support and the first face, that is configured to reflect light that is emitted from the first face back into the substrate that is transparent to optical radiation in the predetermined wavelength range, upon application of voltage across the diode region.    
   
   
       6 . A light emitting diode according to  claim 1  further comprising: 
 an optical element adjacent the first face, opposite the diode region.    
   
   
       7 . A light emitting diode according to  claim 1  wherein the first face of the substrate includes therein at least one groove that defines, in cross-section, the plurality of pedestals in the substrate.  
   
   
       8 . A light emitting diode according to  claim 7  wherein the pedestals are triangular pedestals.  
   
   
       9 . A light emitting diode according to  claim 7  wherein the grooves include tapered and/or curved sidewalls.  
   
   
       10 . A light emitting diode according to  claim 7  wherein the grooves include a beveled and/or curved floor.  
   
   
       11 . A light emitting diode according to  claim 9  wherein the grooves include a beveled and/or curved floor.  
   
   
       12 . A light emitting diode according to  claim 7  wherein the first and second faces of the substrate comprise square perimeters.  
   
   
       13 . A light emitting diode according to  claim 7  wherein the first face of the substrate comprises a textured surface.  
   
   
       14 . A light emitting diode according to  claim 1  wherein the first face of the substrate includes therein an array of via holes that defines, in cross-section, the plurality of pedestals in the substrate.  
   
   
       15 . A light emitting diode according to  claim 14  wherein the via holes include tapered and/or curved sidewalls.  
   
   
       16 . A light emitting diode according to  claim 14  wherein the via holes include a flat, beveled and/or curved floor.  
   
   
       17 . A light emitting diode according to  claim 15  wherein the via holes include a flat, beveled and/or curved floor.  
   
   
       18 . A light emitting diode according to  claim 14  wherein the first and second faces of the substrate comprise square perimeters.  
   
   
       19 . A light emitting diode according to  claim 14  wherein the first face of the substrate comprises a textured surface.  
   
   
       20 . A light emitting diode according to  claim 14  wherein the array of via holes comprises an array of tapered and/or curved via holes.  
   
   
       21 . A light emitting diode according to  claim 1  wherein the diode region comprises a peripheral portion, at least one central portion that is enclosed by the peripheral portion and at least one emission region that is confined to within the at least one central portion and does not extend onto the peripheral portion.  
   
   
       22 . A light emitting diode according to  claim 1  further comprising: 
 a plurality of emission regions on the diode region, a respective one of which is confined to within a respective one of the pedestals and does not extend beyond the respective one of the pedestals.    
   
   
       23 . A light emitting diode according to  claim 7  further comprising: 
 a plurality of electrodes on the diode region, a respective one of which is confined to within a respective one of the pedestals and does not extend beyond the respective one of the pedestals.    
   
   
       24 . A light emitting diode according to  claim 14  further comprising: 
 at least one electrode on the diode region that does not overlap the via holes.    
   
   
       25 . A light emitting diode according to  claim 1 , wherein the substrate comprises silicon carbide and wherein the diode region comprises gallium nitride.  
   
   
       26 . A light emitting diode comprising: 
 a substrate that is between about 100 μm and about 1000 μm thick, having first and second opposing faces, that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face; and    a diode region on the second face that is configured to emit light in the predetermined wavelength range into the substrate that is transparent to optical radiation in the predetermined wavelength range, upon application of voltage across the diode region.    
   
   
       27 . A light emitting diode comprising: 
 a substrate having first and second opposing faces, that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face; and    a diode region on the second face that extends continuously across the plurality of pedestals and that is configured to emit light in the predetermined wavelength range into the substrate that is transparent to optical radiation in the predetermined wavelength range, upon application of voltage across the diode region.