Surface plasmon-enhanced crater-shaped 3D vertical structure LED structure and preparation method

Abstract

The invention discloses a surface plasmon enhancement volcanic-vent 3D vertical structure LED structure and a preparation method thereof. The method is characterized by preparing volcanic-vent surfaceplasmons on the p-GaN surface to couple a three-dimensional quantum well light-emitting array, and introducing the surface plasmons to the vertical structure LED structure to couple quantum wells through a volcanic-vent interface, so that not only internal quantum efficiency of the vertical structure LED structure can be improved through coupling between the surface plasmons and the quantum wells, but also carrier injection efficiency of the surface plasmon enhancement LED device can be improved greatly through the volcanic-vent coupling; and besides, through 3D arrangement design of the volcanic-vent morphology and the quantum well light-emitting array, exciton energy in the light-emitting region is allowed to be coupled to the surface plasmons more favorably, and then, photons are radiated out and emitted from the surface of the device, so that light extraction efficiency of the vertical structure LED device can be enhanced. The 3D multi-functional composite vertical structure LED structure has a practical popularization and application value.

Description

technical field [0001] The invention belongs to the technical field of semiconductor light-emitting diodes, and in particular relates to a surface plasmon enhanced crater-type 3D vertical structure LED structure and a preparation method. Background technique [0002] Gallium nitride (GaN)-based light emitting diode (Light Emitting Diode, hereinafter referred to as LED) has the advantages of wide bandgap, stable performance, and high electron drift saturation rate, and has great application potential and broad market prospects in the field of high-brightness light-emitting diodes. At present, the vertical structure LED makes the current evenly distributed in the chip, which solves the heat dissipation problem well and improves the light efficiency to a certain extent, but the energy loss (including non-radiative recombination and total reflection absorption) that affects light emission still exists. In order to further improve the internal quantum efficiency and external quan...

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Problems solved by technology

For example, by reducing the thickness of p-GaN to reduce the coupling distance between the metal particles on the LED surface and the quantum well , Nanotechnology, 19, 345201-1-345201-4(2008)], this coupling method is simple to design, but it is difficult to further enhance the coupling strength by reducing the thickness of p-GaN; In this method, metal particles that generate surface plasmons are embedded in the p-type GaN layer near the quantum wells to achieve coupling [C.Y.Cho, K.S.Kim, S.J.Lee, M.K.Kwon, H.Ko, S.T.Kim, G.Y. Jung, and S.J Park, Surface plasmon-enhanced light-emitting diodes with silver nanoparticles and SiO2nano-disksembedded in p-GaN, Appl.Phys.Lett., 99, 041107 (2011)], this coupling method can achieve any coupling distance , but it is difficult to avoid the problem of metal diffusion to the active area and the influence of metal on the quality of p-GaN materials; in the past two years, a coupling method that avoids the material growth process has emerged. In the p-GaN of conventional LED epitaxial wafers, Two-dimensional nanohole arrays are prepared on the GaN layer, and metal particles that can generate surface plasmons are deposited on the bottom of the holes [Patent No.: CN 103219442 A]. Although this coupling method does not need to consider many complicated factors such as material growth, the The carrier injection efficiency of the light-emitting region under the nanohole with a coupling-enhancing effect is very low, which seriously affects the effect of surface plasmon resonance coupling-enhanced luminescence

In addition, the light extraction efficiency of the device in the above-mentioned method is still limited by the two-dimensional planarization of the quantum well light-emitting region, which in turn affects the overall light extraction efficiency of the device.

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