Light emitting enhancement and angle-resolved property of surface textured GaN-based vertical LED

The performances of GaN-based vertical light emitting diodes with surface texture of GaN cones were studied. The cones were fabricated by inductively coupled plasma reactive ion etching with Cr mask, which can enhance the light intensity by about 95 % at injection current of 350 mA. Angle and wavelength-resolved far-field spectra were measured, and the maximum light enhancement lies at about ±15°–50° respect to normal direction. This is because of the successive reflection of light by the sidewall of cones, which can be concluded from the far-field pattern that the Fabry-Perot like resonance of patterned LED disappears compared to the original device. The polarization property of patterned LED was also analyzed, which can explain the increasing of enhancement ratio with injection current.