JP2012169396A - White light-emitting diode containing fluorescent layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white light-emitting diode equipped with a fluorescent layer.SOLUTION: The white light-emitting diode equipped with a fluorescent layer includes a gallium nitride buffer layer, an n-type gallium nitride layer, a multiple quantum well aluminum gallium nitride layer, a p-type gallium nitride layer, a transparent conductive layer, and an indium terbium oxide fluorescent layer, which are deposited in this order on a sapphire substrate, and further includes a plus-pole metal connection layer connected to the p-type gallium nitride layer, and a minus-pole metal connection layer connected to the n-type gallium nitride layer. When the plus-pole metal connection layer and the minus-pole metal connection layer, among them, are connected to an external plus power terminal and a minus power terminal respectively, the multiple quantum well aluminum gallium nitride layer emits beam by electron positive hole re-coupling, and said beam is emitted outward by way of the p-type gallium nitride layer, the transparent conductive layer, and the indium terbium oxide fluorescent layer. The fluorescence of the indium terbium oxide fluorescent layer converts the beam emitted by the multiple quantum well aluminum gallium nitride layer to the emission light in white.

Description

  The present invention relates to a type of white light emitting diode, and more particularly to a type of white light emitting diode including a transparent conductive layer of indium terbium oxide having fluorescent properties.

  Since light emitting diodes have high efficiency light emission characteristics, they have already been widely applied to light emitting sources and display devices. The light emission principle of a light emitting diode is that when a voltage is applied in the forward direction, the pn junction between the p-type semiconductor layer and the n-type semiconductor layer generates electron-hole recombination and converts the electrical energy into the corresponding light energy. In this way, emitted light is generated. The wavelength of the emitted light is determined by the size of the band gap. Therefore, by combining a p-type semiconductor layer and an n-type semiconductor having an appropriate composition, the necessary band gap can be realized and the necessary visible light can be generated. Can do.

  The emitted light generated by a general light emitting diode has an ultraviolet light component. Therefore, usually, high-energy ultraviolet light is compared using the fluorescent action of fluorescent powder added to the transparent fluorescent resin layer. Converted into visible light of low energy for use.

  However, a drawback of the above-described known technique is that the transparent fluorescent resin body layer has a problem of aging of the resin body and affects the emitted light quality of the light emitting diode. For this reason, it is necessary to manufacture a white light emitting diode having a semiconductor fluorescent layer having a fluorescent action in a semiconductor process, and to solve the above-mentioned problems of the known technology.

  The main object of the present invention is to provide a white light emitting diode having a fluorescent layer, which includes a sapphire substrate, a gallium nitride buffer layer, an n-type gallium nitride layer, a multiple quantum well aluminum gallium nitride layer, a p-type nitride. It includes a gallium layer, a transparent conductive layer, an indium terbium oxide phosphor layer, a negative electrode metal connection layer, and a positive electrode metal connection layer. Among them, the gallium nitride buffer layer, the n-type gallium nitride layer, the multiple quantum well aluminum gallium nitride layer, the p-type gallium nitride layer, the transparent conductive layer, and the indium terbium oxide fluorescent layer are sequentially deposited on the sapphire substrate, and the negative electrode metal connection layer Is connected to the n-type gallium nitride layer and used for connection to the external negative power supply terminal, and the positive electrode metal connection layer is located on the indium terbium oxide fluorescent layer and transparent through the indium terbium oxide fluorescent layer Connected to the conductive layer and used to connect to the external positive power supply terminal, whereby current flows from the positive electrode metal connection layer to the transparent conductive layer, p-type gallium nitride layer, indium terbium oxide fluorescent layer, and n-type gallium nitride layer To the negative electrode metal connection layer, and light is emitted from the multiple quantum well aluminum gallium nitride layer. And, this ray is, p-type gallium nitride layer, as a transparent conductive layer and the indium oxide terbium phosphor layer, is and emitted been converted to white light to the outside equipped with fluorescence properties indium oxide terbium fluorescence layer.

The invention of claim 1 is a white light emitting diode having a fluorescent layer, wherein the white light emitting diode is used to generate white light,
A sapphire substrate,
A gallium nitride buffer layer deposited on the sapphire substrate;
An n-type gallium nitride layer deposited on the gallium nitride buffer layer;
A multiple quantum well aluminum gallium nitride layer deposited on the n-type gallium nitride layer and partially exposed;
A p-type gallium nitride layer deposited on the multi-quantum well aluminum gallium nitride layer; a transparent conductive layer deposited on the p-type gallium nitride layer;
An indium terbium oxide phosphor layer deposited on the transparent conductive layer and having a through hole;
A negative electrode metal connection layer deposited on the indium terbium oxide phosphor layer and electrically connected to the transparent conductive layer through the through hole and electrically connected to a negative terminal of an external power source;
A positive electrode metal connection layer deposited on the p-type gallium nitride layer and electrically connected to a positive terminal of an external power source;
A white light-emitting diode characterized by including
According to a second aspect of the present invention, in the white light emitting diode according to the first aspect, the proportional range of indium oxide and terbium contained in the indium terbium oxide phosphor layer is In ₂ O ₃ : Tb = 95: 5 to 70:30. A white light emitting diode is provided.
According to a third aspect of the present invention, there is provided the white light emitting diode according to the first aspect, wherein the indium terbium oxide phosphor layer is deposited by an RF reactive magnetically controlled sputtering method.
According to a fourth aspect of the present invention, in the white light emitting diode according to the first aspect, the multi-quantum well aluminum gallium nitride layer comprises a plurality of alternately deposited thin aluminum gallium nitrides having different band gaps, and a low band The white light-emitting diode is characterized by having a quantum well formed by a gap layer.

  The white light-emitting diode of the present invention does not need to add fluorescent powder into a transparent resin body to form a resin phosphor layer and convert ultraviolet light into visible light, and is transparent directly in the semiconductor process of RF reactive magnetically controlled sputtering. An indium terbium oxide fluorescent layer having a fluorescent action can be deposited on the conductive layer, thereby generating outgoing light having a white light spectrum.

It is a display figure of the white light emitting diode provided with the fluorescent layer of this invention. It is a photoluminescence spectrum of the white light emitting diode of the Example of this invention. It is a photoluminescence spectrum of the white light emitting diode of another Example of this invention. It is an electroluminescence spectrum of the white light emitting diode of the Example of this invention. It is an electroluminescence spectrum of the fluorescent layer of the white light emitting diode of the Example of this invention. It is an electroluminescence spectrum of the white light emitting diode of another Example of this invention. It is an electroluminescence spectrum of the fluorescent layer of the white light emitting diode of another Example of this invention. It is a light emission photograph of the white light emitting diode provided with the 10% indium terbium oxide phosphor layer of the present invention (at 20 mA). It is the light emission photograph of the white light emitting diode provided with the 20% indium terbium oxide fluorescent layer of the present invention (at 20 mA).

  In order to describe in detail the technical contents, structural features, and objects to be achieved of the present invention, examples will be described below in combination with the drawings.

  Please refer to FIG. FIG. 1 is a display diagram of a white light emitting diode having a phosphor layer according to the present invention. The white light emitting diode including the fluorescent layer of the present invention includes a sapphire substrate 10, a gallium nitride buffer layer 20, an n-type gallium nitride layer 30, a multiple quantum well aluminum gallium nitride layer (Multiple Quantum Well, MQW) 40, and a p-type gallium nitride. The layer 50, the transparent conductive layer 60, the indium terbium oxide phosphor layer 70, the negative electrode metal connection layer 80, and the positive electrode metal connection layer 90 are used to generate white light.

  The gallium nitride buffer layer 20, the n-type gallium nitride layer 30, the multiple quantum well aluminum gallium nitride layer 40, the p-type gallium nitride layer 50, the transparent conductive layer 60 and the indium terbium oxide fluorescent layer 70 are sequentially deposited on the sapphire substrate 10. A part of the n-type gallium nitride layer 30 is exposed and used to electrically connect the negative electrode metal connection layer 80, and the negative electrode metal connection layer 80 is connected to the negative terminal V− of the external power source. .

  The positive electrode metal connection layer 90 is used to connect to the positive terminal V + of the external power source and is located on the indium terbium oxide fluorescent layer 70. The indium terbium oxide phosphor layer 70 has a through hole, whereby the positive electrode metal connection layer 90 is electrically connected to the transparent conductive layer 60 through the through hole.

  The multi-quantum well aluminum gallium nitride layer 40 includes a plurality of alternately deposited and different band gap thin aluminum gallium nitride layers. Of these, the quantum well formed by the low band gap layer is used to generate electrons and holes. Easily localized together, thereby increasing the emission intensity.

  When the current reaches the negative electrode metal connection layer 80 from the positive electrode metal connection layer 90 through the transparent conductive layer 60, the p-type gallium nitride layer 50, the multiple quantum well aluminum gallium nitride layer 40, and the n-type gallium nitride layer 30, the multiple quantum The well aluminum gallium nitride layer 40 emits light by electron-hole recombination, and the light passes through the p-type gallium nitride layer 50, the transparent conductive layer 60, and the indium terbium oxide fluorescent layer 70, and exhibits fluorescence characteristics. The indium terbium oxide phosphor layer 70 is converted into white light emission light and emitted to the outside.

The indium terbium oxide fluorescent layer 70 of the present invention is a transparent thin film, the main component is indium terbium oxide (Terium Indium Oxide), the chemical formula is In ₂ O ₃ : Tb, and generally TIO. Among them, the best proportional range of indium oxide and terbium is In ₂ O ₃ : Tb = 95: 5 to 5:95. The indium terbium oxide phosphor layer 70 is deposited on the transparent conductive layer 60 using a semiconductor process of RF reactive magnetic control sputtering.

  For a clear understanding of the features of the present invention, please refer to FIGS. Among them, FIG. 2 is a photoluminescence spectrum of the white light emitting diode of the embodiment of the present invention, and the proportion of indium oxide and terbium is 90:10. FIG. The photoluminescence of the white light emitting diode of Example 1 is shown, and the proportion of indium oxide and terbium is 80:20. 2 and 3 show photoluminescence changes in the temperature range from 10 K to 300 K, and FIGS. 2 and 3 show broad absorption characteristics around 575 nm and 565 nm, respectively.

  4 and 5 show the electroluminescence spectrum of the white light emitting diode and the fluorescent layer thereof according to the embodiment of the present invention. The ratio of indium oxide and terbium in FIG. 4 is 90:10, and the current is 100 mA. As can be seen from FIG. 4, the white light emitting diode of this example has 385 nm ultraviolet light. As can be seen from FIG. 5, the fluorescent layer has an orbital transition from 450 nm to 700 nm, that is, a transition from the D orbital to the F orbital, and the wavelength corresponding to the transition is shown in the figure. .

  Next, please refer to FIG. 6 and FIG. These are respectively the electroluminescence spectra of the white light emitting diode and the phosphor layer thereof according to another embodiment of the present invention, and the proportion of indium oxide and terbium is 80:20, and the current is 100 mA. In FIG. 6, the white light emitting diode has 385 nm ultraviolet light as in the previous example, and in FIG. 7, its fluorescent layer has an orbital transition from 450 nm to 700 nm similar to that shown in FIG. In the figure, the wavelength corresponding to the transition is also shown.

  Accordingly, as clearly understood from the spectra of FIGS. 2 to 7, the white light emitting diode of the present invention can reliably generate white light and is used to provide a high-quality light source. It can be applied to a light source or a general illumination source. In order to more specifically represent the white light emitting diode having the above-described phosphor layer of the present invention, refer to the photographs of FIGS. 8 is a photograph of white light emitted from a gallium nitride white light emitting diode having a 10% indium terbium oxide phosphor layer (ie, the ratio of indium oxide and terbium is 90:10), and FIG. 9 is a 20% oxide. It is a photograph of white light emitted from a gallium nitride white light emitting diode having an indium terbium fluorescent layer (ie, the ratio of indium oxide and terbium is 80:20), and the conduction current is 20 mA.

  The above description is only an example of the present invention, and does not limit the scope of the present invention. Any equivalent changes and modifications that can be made based on the scope of the claims of the present invention are all described in the present invention. Shall belong to the scope covered by the rights.

10 sapphire substrate 20 gallium nitride buffer layer 30 n-type gallium nitride layer 40 multiple quantum well aluminum gallium nitride layer 50 p-type gallium nitride layer 60 transparent conductive layer 70 indium terbium oxide fluorescent layer 80 negative electrode metal connection layer 90 positive electrode metal connection layer V + Positive terminal V- Negative terminal

Claims (4)

In a white light emitting diode with a fluorescent layer, the white light emitting diode is used to generate white light,
A sapphire substrate,
A gallium nitride buffer layer deposited on the sapphire substrate;
An n-type gallium nitride layer deposited on the gallium nitride buffer layer;
A multiple quantum well aluminum gallium nitride layer deposited on the n-type gallium nitride layer and partially exposed;
A p-type gallium nitride layer deposited on the multi-quantum well aluminum gallium nitride layer; a transparent conductive layer deposited on the p-type gallium nitride layer;
An indium terbium oxide phosphor layer deposited on the transparent conductive layer and having a through hole;
A negative electrode metal connection layer deposited on the indium terbium oxide phosphor layer and electrically connected to the transparent conductive layer through the through hole and electrically connected to a negative terminal of an external power source;
A positive electrode metal connection layer deposited on the p-type gallium nitride layer and electrically connected to a positive terminal of an external power source;
A white light-emitting diode comprising: 2. The white light-emitting diode according to claim 1, wherein a proportional range of indium oxide and terbium contained in the indium terbium oxide phosphor layer is In ₂ O ₃ : Tb = 95: 5 to 70:30, White light emitting diode.   2. The white light emitting diode according to claim 1, wherein the indium terbium oxide phosphor layer is deposited by RF reactive magnetically controlled sputtering.   2. The white light-emitting diode according to claim 1, wherein the multiple quantum well aluminum gallium nitride layer comprises a plurality of alternately deposited thin aluminum gallium nitrides of different band gaps and a low band gap layer forms. A white light-emitting diode characterized by comprising:

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