TWI464901B - Light emitting device with magntic field - Google Patents

Description

Magnetic illuminating device

The present invention relates to a light emitting device, and more particularly to a magnetic light emitting device.

A light emitting device such as a Light Emitting Diode (LED) can emit light depending on the driving electron flow through the active layer of the LED. However, if the current density distributed throughout the light-emitting region is uniform, the uniformity of light emission is lowered. Still further, in conventional designs, the opaque top electrode is typically disposed in a central region of the illuminating region. According to the above, the current density under the top electrode is larger than other regions and more light can be emitted. However, based on the top electrode being opaque, the illumination below the top electrode is covered. Since the top electrode of a conventional LED covers the highest intensity illumination in the central region, the output brightness is reduced.

Accordingly, in the related art, improvement of LED light-emitting output efficiency still needs further development.

The present invention provides a magnetic light-emitting device that employs a Hall effect to arrange electrode layer positions so as to increase luminous output efficiency.

An exemplary embodiment of the present invention provides a magnetic light emitting device including a light emitting structure and a first magnetic source layer. The light emitting structure includes a first semiconductor structure layer, a second semiconductor structure layer, an active layer, a first electrode layer and a second electrode a layer, wherein the active layer is interposed between the first semiconductor structure layer and the second semiconductor structure layer. The first magnetic source layer is integrated into the light emitting structure for generating a magnetic field in the light emitting structure.

An exemplary embodiment of the present invention provides a magnetic light emitting device including a light emitting structure, a light transmitting magnetic source layer, a first electrode layer, and a second electrode layer. The light emitting structure includes a first semiconductor structure layer, a second semiconductor structure layer, and an active layer interposed between the first semiconductor structure layer and the second semiconductor structure layer. The light transmissive magnetic source layer is disposed on the first semiconductor structure layer to generate a magnetic field. The first electrode layer is disposed on the light transmitting magnetic source layer. The second electrode layer is disposed on the second semiconductor structure layer and on the opposite side of the first electrode layer.

According to various exemplary embodiments of the present invention, the magnetic source layer is integrated into the structure of the light emitting device. In other words, the magnetic field can be self-supplied on a single wafer. A single illuminator is easy to package in a single wafer.

The foregoing general description and the following detailed description are exemplary and are in the

The accompanying drawings included in the present specification are intended to provide a more obvious understanding of the invention and The drawings illustrate various exemplary embodiments of the invention, and are in accordance

The present invention proposes a light-emitting device incorporating a magnetic source layer to increase light output efficiency. Many exemplary embodiments are described to illustrate the invention, but the invention is not limited to a plurality of exemplary embodiments. Further, various demonstrations Combinations of the embodiments can be used to form other exemplary embodiments.

In the physical phenomenon, the Hall effect is that when a current flows through the wire and a magnetic field is applied laterally, then, for example, the current path of the electron current is laterally shifted based on the magnetic field Lorenz force of F=q*v*B. The present invention incorporates a Hall effect into an LED in accordance with the principles of the Hall effect.

1 illustrates a cross-section of a magnetic LED structure in accordance with an exemplary embodiment of the present invention. In Fig. 1, an LED is taken as an example. For example, the LED includes a bottom electrode layer 100, a light emitting structure 102, and a top electrode layer 104, and the light emitting structure 102 includes a first semiconductor structure layer 102a, an active layer 102b, and another semiconductor structure layer 102c, wherein the first semiconductor structure The layer 102a is, for example, a P-type doped semiconductor structure layer, the active layer 102b for emitting light is a combination of electrons and holes, and the other semiconductor structure layer 102c is, for example, an N-type doped layer. The top electrode layer 104 may not be disposed in the center of the light emitting region 108.

When operating, current flows from the bottom electrode layer 100 to the top electrode layer 104. however. If a magnetic field is applied in one direction, such as the direction of the magnetic field 106, a Lorenz force is generated to offset the current. Accordingly, the lateral shift of the current flows efficiently through the active layer 102b, but does not directly move to the top electrode layer 104. Based on this, the driving current can more efficiently illuminate the active layer 102b.

According to the physical process shown in Figure 1, the magnetic field needs to be increased. The invention proposes a lighting device and integrates the magnetic source in particular for implementation. Accordingly, each of the light-emitting devices can operate separately in a magnetic field environment.

2 through 5 illustrate cross-sections of a light emitting device structure utilizing a package to integrate a magnetic source layer in accordance with various exemplary embodiments of the present invention. Please refer to Figure 2, For example, the doped semiconductor structure layer 202 is disposed over the substrate 200. The active layer 204 is formed over the doped semiconductor structure layer 202. Another doped semiconductor structure layer 206 is formed over the active layer 204. Here, the doped semiconductor structure layer may be a single layer or a stacked layer according to the design structure. However, the invention is not particularly limited to the semiconductor structure layer. Still further, for example, a transparent conductive (TCL) 208 may be further formed over the semiconductor structure layer 202. As in the prior art, TCL 208 contacts electrode layer 212 to increase luminous efficiency. Further, a reflector can be implemented depending on the direction of light emission. In this example, the electrode layer 210 is disposed on the semiconductor structure layer 202. Another electrode layer 212 is disposed on the TCL layer 208. Generally speaking, this structural part is a conventional LED example. The basic LED structure of the present invention that does not include a magnetic source layer is not necessarily limited to a particular LED.

In an exemplary embodiment, in order to implement the magnetic source layer, a package structure may be employed to integrate the magnetic source layer to the light emitting device, wherein the package structure is, for example, a flip chip package. The magnetic source layer 218 may be formed over a submount 220. The magnetic source layer 218 is, for example, a ferromagnetic layer having a magnetization direction. The material forming the ferromagnetic layer includes, for example, iron, cobalt, nickel, rhodium, and the like. Furthermore, in addition to the artificial magnetic material, the natural magnet can be used in the manner in which it is applied. However, the magnetic field square should be properly arranged. The LED and magnetic source layer 218 are then packaged on the package substrate 220 by solder structures 214 and 216, wherein the solder structures 214 and 216 are, for example, solder bumps or directly soldered, which in turn, as shown in FIG. 5, also serves as the electrode layer 210'. Used for electrode layer 212'. Accordingly, the magnetic source layer 218 can be produced in the LED Magnetic field. In an exemplary embodiment, if the magnetic direction of the magnetic source layer 218 is the direction of the plane of the drawing, a magnetic field can be generated in the magnetic field direction 106 of FIG. The magnetic source layer 218 and the LED configuration disposed on the package substrate 220 can be used separately, wherein the preset magnetic field can be self-supplied on a single wafer.

Referring to FIG. 3, the exemplary embodiment is similar to the exemplary embodiment shown in FIG. 2, and another magnetic source layer 224 may be further formed on the bottom surface of the substrate 200, wherein the magnetic film 222 is, for example, a thin film metal magnetic material. The effect from the magnetic source layer 224 is the same. Accordingly, the magnetic field in the LED can be further improved or regionally adjusted.

In FIG. 4, when the magnetic source layer 224 is formed directly over the doped semiconductor structure layer 202, the structure can be further modified with the removal substrate 200, as compared to FIG. Since the two electrode layers 210 and 212 are on the same side of the LED, the doped semiconductor structure layer 202 can still apply an operating voltage through the electrode layer 210.

The foregoing exemplary package structure is based on solder structures 214 and 216. However, this is not the only way to package. For example, another packaging method can refer to FIG. 5. The electrode layers 212' and 210' in Fig. 5 can be formed by, for example, electroplating. The electrode layers 212' and 210' are then packaged on a package substrate 226. In other words, encapsulating the magnetic source layer on the package substrate can employ any suitable packaging process.

6 is a cross-sectional view showing the structure of a light-emitting device incorporating a strip-shaped magnetic source layer in accordance with an exemplary embodiment of the present invention. Referring to FIG. 6 , the magnetic layer 232 may be formed between the substrate 200 and the LED 233 according to an Epitaxial Lateral Overgrowth (ELOG) method. In an exemplary embodiment, the magnetic layer 232 may be formed on the substrate 200 and shaped in accordance with a predetermined pattern. The lower semiconductor layer of LED 233 can then be grown using the ELOG process.

7 through 8 illustrate cross-sections of various light emitting device structures incorporating an integrated magnetic source layer in accordance with various exemplary embodiments of the present invention. According to the same point of view, the magnetic source layer can be integrated into the LED as a light-emitting device in various ways. The various exemplary embodiments described below are some exemplary embodiments of the present invention, but the present invention is not limited thereto.

In the alternative configuration shown in FIG. 8, the LED structure of another exemplary embodiment includes a doped semiconductor structure layer 202, an active layer 204, and another doped semiconductor structure layer 206. Further, TCL 208 can also be included therein. This LED structure is used to implement a magnetic source layer and is exemplified in the exemplary embodiments described later. The bottom electrode layer 234 is formed on one side of the doped semiconductor structure layer 202, and the other electrode layer 236 is formed on the opposite side of the bottom electrode layer 234 on the TCL 208. The area of the TCL 208 that is not covered by the electrode layer 236 is the light-emitting area 240 that is expected to be formed. Based on this structure, for example, the magnetic source layer 238 may be formed over the electrode layer 236, and is preferably formed only over the electrode layer 236. The magnetic field generated at the LED is, for example, the magnetic field direction 106 shown in FIG. In a further improvement shown in FIG. 8, another magnetic source layer 244 may be formed over the electrode layer 234.

9 and 10 illustrate perspective views of the structures of Figs. 7 and 8 in accordance with various exemplary embodiments of the present invention. In Figures 9 and 10, the electrode layer 236 and the magnetic source layer 238 may be formed in a pattern, such as a strip pattern, in accordance with a pattern to thereby generate a predetermined magnetic field. In other words, the top electrode layer having a magnetic field can be generated according to a magnetic field for increasing the efficiency of the light-emitting output, thereby being arranged in a single small area or in some small areas.

For further improvement, the magnetic source layer can be used in other ways. Implementation. 11 through 27 illustrate cross-sectional views of various light emitting device structures incorporating an integrated magnetic source layer in accordance with various exemplary embodiments of the present invention. The bottom electrode layer 252 may be disposed on the bottom surface of the doped semiconductor structure layer 202 in FIG. However, in this exemplary embodiment, the magnetic source layer 250 may be disposed between the LED and the electrode layer 254. In a preferred manner, the magnetic source layer 250 can be disposed between the TCL 208 and the electrode layer 254. In another preferred manner, the magnetic source layer 250 can further be permeable to light and thus extend with the surface of the TCL 208. Here, the metal is usually opaque in terms of physical properties. However, when the thickness of the metal is sufficiently thin, it can be light transmitted. On the other hand, if the light emitting direction faces the electrode layer 252, the magnetic source layer 250 does not have to be transparent. In the exemplary embodiment, the magnetic source layer 250 is, for example, a ferromagnetic material of thin film metal or a ferromagnetic material that is transparent to light under other conditions. This structure can generate a transverse magnetic field more efficiently. In FIG. 12, in addition to the structure of FIG. 11, another magnetic source layer 256 may be formed at the bottom of the light emitting device, for example, formed on the electrode layer 252. The magnetic source layer 256 does not need to be transparent.

In another exemplary embodiment of FIG. 13, magnetic source layer 258 can be disposed on top of the light emitting device. For example, the magnetic source layer 258 can overlie the TCL 208 and the electrode layer 254. Similarly, the magnetic source layer 258 may be light transmissive or opaque depending on the direction of illumination. In FIG. 14, the magnetic source layer 260 is additionally formed at the bottom. The magnetic source layer 260 can be considered as a reflective layer for reflecting light.

In FIG. 15, comparing FIG. 13 further, the magnetic source layer 262 may be a light-emitting region covering only a portion and not covering the electrode layer 254. In Fig. 16, the magnetic source layer 264 is additionally formed at the bottom. Magnetic source layer 264 can be viewed as a reflective layer for reflecting light.

In FIG. 17, if the light emitting direction is toward the electrode layer 252, the electrode layer may be TCL. A reflective layer 266 can then be formed on one side having the electrode layer 254. Then, the magnetic source layer 268 can be formed, for example, on the reflective layer 266 and the electrode layer 254. Still further, similar to other exemplary embodiments, the permeable magnetic source layer can be disposed on the electrode layer 252 as desired. Furthermore, the electrode layer 252 as shown in FIG. 18 may cover only a small area of the doped semiconductor structure layer 202.

On the other hand, in various exemplary embodiments, when the LEDs are designed to arrange the two electrode layers on the same side, the magnetic source layer can be integrated into the LED. According to the structure of FIG. 17, the electrode layer 234 in FIG. 19 may be formed on the extension of the doped semiconductor structure layer 202, but on the same side as the electrode layer 236. A magnetic source layer 238 may be formed over the electrode layer 236. The structure shown in Fig. 20 is based on the structure shown in Fig. 8. Electrode layer 234 is formed in an extension of doped semiconductor structure layer 202. The magnetic source layer 244 can be disposed directly over the doped semiconductor structure layer 202.

The structure shown in Fig. 21 is based on the structure shown in Fig. 11. The electrode layer 252 is disposed in an extension of the doped semiconductor structure layer 202. Similarly, the electrode layer structures shown in Figs. 22 to 27 are based on the structures shown in Figs. However, in the electrode layer structure shown in 22 to 27, when the magnetic source layer is rearranged, the electrode layer is disposed in the extended region of the doped semiconductor structure layer 202.

In other words, the magnetic source layer can be integrated into the LED as a light-emitting device having a magnetic field. The actual implementation can be implemented according to different methods. For example, a plurality of exemplary embodiments and individual combinations thereof.

Regarding various options, for example, the luminescent surface may be somewhat roughened to increase the illuminating quality. The ELOG technique shown in Figure 6 can use a magnetic layer as a mask on a semiconductor substrate. The semiconductor layer is then grown by a process such as Metal Organic Chemical Vapor Deposition (MOCVD) or Molecular Beam Epitaxy (MBE). Accordingly, the magnetic layer is embedded in the light emitting device.

Still further, the P-N junction optical element can be formed of an inorganic or organic material. For example, inorganic semiconductor materials include GaAs, InP, GaN, GaP, AlP, AlAs, InAs, GaSb, InSb, Cds, CdSe, ZnS, and ZnSe, and the like. Organic semiconductor materials include polymers or conventional organic materials. The soldering method may be, for example, die bonding, flip chip bonding, metal bonding, wafer bonding, or the like. The solder material may be, for example, Silver Glue, Goldtin, Au bump, metal bump, and the like.

In another aspect, the reflective layer can be a reflector or a dielectric reflective layer, such as a Distributed Bragg Reflector (DBR) structure, wherein the dielectric material can include, for example, TiO ₂ , TaO ₅ , SiO ₂ , Mb ₂ O _{5 .} , SeO ₂ , ZnS, ZnO or MgF ₂ . The substrate can include, for example, Si, Sic, GaN, GaP, GaAs, sapphire, Zno, or AlN. The soft magnetic material may include, for example, Fe, Co, Ni, Tb, Al, or a combination thereof. The magnetic film may include, for example, Pt, Co, Sm, Fe, Ni, Cu, Cr, or Tb, formed by a coating process.

In addition to this, the magnetic material may include a magnet material such as Nd, Fe, Pg, Co, Ni, Mn, Cr or Rb, or for example MnO _x , FeO _x , CoO, CuO, V _x O _x , Cr ₂ O ₃ , CrS, MnS, MnSe, MnTe, MnF _x , FeF _x , CoF _x , NiF _x , VCl _x , CrCl _x , FeCl _x , CoCl _x , NiCl _x , CuCl _x , CuBr _x , CrSb, MnAs, MnBi, Cr , α-Mn, MnCl ₂ .4H ₂ O, MnBr ₂ .4H ₂ O, CuCl ₂ .2H ₂ O, Co(NH ₄ ) _x (SO ₄ ) _x Cl ₂ .6H ₂ O, FeCo ₃ , or FeCo ₃ .2MgCO ₃ and other ceramic materials.

The material or detailed structure of the above elements may be modified somewhat without departing from the features of the invention.

While the present invention has been described above by way of exemplary embodiments, it is not intended to limit the invention, and it is to be understood by those skilled in the art without departing from the spirit and scope of the invention. The teachings, disclosures, or stipulations of the invention are subject to a few changes and modifications, and the scope of the invention is defined by the scope of the appended claims.

100‧‧‧ bottom electrode layer

102‧‧‧Lighting structure

102a, 102c‧‧‧ semiconductor structural layer

102b, 204‧‧‧ active layer

104‧‧‧Top electrode layer

106‧‧‧Magnetic direction

108, 240‧‧‧Lighting area

200‧‧‧Base

208‧‧‧Transparent conductive layer

202, 206‧‧‧ semiconductor structural layer

210, 212, 210', 212'‧‧‧ electrode layers

214, 216‧‧‧ welded structure

220, 226‧‧‧ package substrate

218, 224, 238, 244, 250, 256, 258, 260, 262, 264, 268‧‧ ‧ magnetic source layer

222‧‧‧ Magnetic film

233, 234‧‧‧Lighting diodes

232‧‧‧Magnetic layer

236, 252, 254‧‧ ‧ electrode layer

266‧‧‧reflective layer

1 is a cross-sectional view of a magnetic LED structure in accordance with an exemplary embodiment of the present invention.

2 through 5 are cross-sectional views of a light emitting device structure utilizing a package to integrate a magnetic source layer in accordance with various exemplary embodiments of the present invention.

Figure 6 is a cross-sectional view showing the structure of a light-emitting device incorporating a strip-shaped magnetic source layer in accordance with an exemplary embodiment of the present invention.

7 through 8 are integrated magnetic sources in accordance with various exemplary embodiments of the present invention A cross section of the structure of the various illuminators of the layer.

9 and 10 are perspective views of the structure of Figs. 7 and 8 in accordance with various exemplary embodiments of the present invention.

11 through 27 are cross-sectional views of various light emitting device structures incorporating an integrated magnetic source layer in accordance with various exemplary embodiments of the present invention.

200‧‧‧Base

204‧‧‧Active layer

202, 206‧‧‧ semiconductor structural layer

208‧‧‧Transparent conductive layer

210, 212‧‧‧ electrode layer

214, 216‧‧‧ welded structure

218‧‧‧magnetic source layer

220‧‧‧Package substrate

Claims (19)

A magnetic light-emitting device includes: a light-emitting structure comprising: a first semiconductor structure layer; a second semiconductor structure layer; an active layer between the first semiconductor structure layer and the second semiconductor structure layer; An electrode layer electrically connected to the first semiconductor structure layer; and a second electrode layer electrically connected to the second semiconductor structure layer; and a first magnetic source layer integrated in the light emitting structure for A magnetic field is generated in the light emitting structure, wherein the first magnetic source layer covers the light emitting structure and the first electrode layer. The magnetic illuminating device of claim 1, wherein the magnetic field laterally shifts a driving current of the illuminating structure to redistribute the driving current to the illuminating structure. The magnetic illuminating device of claim 1, wherein the first magnetic source layer is a light transmitting magnetic source layer. The magnetic illuminating device of claim 1, wherein the first magnetic source layer comprises a magnetic thin film on the first semiconductor structural layer. The magnetic illuminating device of claim 1, wherein The light emitting structure further includes a reflective layer disposed on the first semiconductor structure layer, and the first magnetic source layer includes a magnetic film on the reflective layer. The magnetic illuminating device of claim 1, wherein the illuminating structure is disposed on a substrate, and the first magnetic source layer is also disposed on a portion of the substrate, the first magnetic source layer Between the substrate and the light emitting structure. The magnetic light-emitting device of claim 1, wherein the first electrode layer and the second electrode layer are respectively disposed on opposite sides of the light-emitting structure. The magnetic illuminating device of claim 1, further comprising a second magnetic source layer disposed on the second electrode layer. The magnetic illuminating device of claim 1, further comprising a reflective layer interposed between the first magnetic source layer and the first semiconductor structural layer. A magnetic light-emitting device includes: a light-emitting structure comprising: a first semiconductor structure layer; a second semiconductor structure layer; an active layer between the first semiconductor structure layer and the second semiconductor structure layer; An electrode layer; and a second electrode layer; and a first magnetic source layer integrated in the light emitting structure for generating a magnetic field in the light emitting structure, wherein the first magnetic source layer comprises: a package substrate layer; and a magnetic film disposed on the package substrate layer; wherein the first electrode layer and the second electrode layer are disposed on the same side of the light emitting structure. The magnetic light-emitting device of claim 10, wherein the first magnetic source layer is encapsulated in the light-emitting structure by the first electrode layer and the second electrode layer. The magnetic illuminating device of claim 10, further comprising a second magnetic source layer formed on an opposite side of the illuminating device for engaging the first magnetic source layer to generate the magnetic field. The magnetic illuminating device of claim 12, wherein the illuminating structure comprises or does not include the substrate. A magnetic light-emitting device includes: a light-emitting structure comprising: a first semiconductor structure layer; a second semiconductor structure layer; an active layer between the first semiconductor structure layer and the second semiconductor structure layer; An electrode layer; and a second electrode layer; and a first magnetic source layer integrated in the light emitting structure for generating a magnetic field in the light emitting structure, wherein the first electrode layer and the second electrode layer are respectively disposed on The opposite side of the light emitting structure, The first magnetic source layer covers the light emitting structure in a portion other than the first electrode layer. The magnetic illuminating device of claim 14, further comprising a second magnetic source layer disposed on the second electrode layer. The magnetic illuminating device of claim 14, wherein the first semiconductor structural layer comprises: a transparent conductive layer contacting the first electrode layer. A magnetic light-emitting device includes: a light-emitting structure comprising: a first semiconductor structure layer; a second semiconductor structure layer; and an active layer interposed between the first semiconductor structure layer and the second semiconductor structure layer; a transparent magnetic source layer disposed on the first semiconductor structure layer to generate a magnetic field; a first electrode layer disposed on the transparent magnetic source layer; and a second electrode layer disposed on the second semiconductor structure layer Located on the opposite side of the first electrode layer. The magnetic illuminating device of claim 17, wherein the magnetic field laterally shifts a driving current of the illuminating structure to redistribute the driving current to the illuminating structure. The magnetic illuminating device of claim 17, further comprising a magnetic source layer disposed on the second electrode layer.