1284995 九、發明說明： 【發明所屬之技術領域】 \ 本發明是有關於一種固態發光元件，特別是指一種發 光二極體。 【先前技術】 由於固態發光元件具有壽命長、省電、體積小、驅動 電壓低、反應速率快、辨識率高等優點，是新一代的光源 • 種類之一，特別是發光二極體，已廣為應用在週遭的曰常 生活中。 參閱圖1、圖2，一般，發光二極體丨包含一基材n、 至少一蟲晶形成在該基材11上的量子單元12、一形成在該 量子單元12頂面的透明導電層13，及二可提供電能的電極 14 〇 该基材11是由晶袼常數與該量子單元相匹配的材料構 成，舉例來說，該量子單元12是屬氮化鎵系的半導體材料 • 時’該基材11則為易於磊晶的藍寶石。 該量子單元丨2自該基材11頂面向上磊晶形成，具有一 第一型披覆層121 ( cladding layer )、一第二型批覆層122， 及一在該第一、二型批覆層121、122之間的活性層123( active layer)，該第一、二型彼覆層i21、i22相對該活性層 123形成量子能障而可以光電效應產生光；該第一、二型彼 覆層121、122分別為n型彼覆層與p型彼覆層；且，一般 為提昇發光效率，均會以複數量子單元為最佳設計，但在 本例與圖示中，為使說明清楚起見，僅以一量子單元12為 5 1284995 例說明。 該透明導電層13以可透光且可使電流分散均句的材料 構成’例如銦錫氧化物（業界習稱ITO)，而可使得以電極 14施加電能時，電流均勻地流通過該量子單元12的活性層 123，而提昇發光效率。 該二電極14彼此相對遠離地與該量子單元12的第— 型彼覆層121以及該透明導電層13毆姆接觸，而可對該量 子單7L 12提供電能使該量子單元12產生光。 田自该二電極14施加電能時，電流經過該透明導電層 13分散流通過該量子單元12，而使該量子單元a以光電 效應產生光子，進而使該發光二極體1向外發光。 由於第一型披覆層121的電阻率遠小於第二型披覆層 122，所以當自該二電極14施加電能時，電流會相對較集 中於電極14的四周，並以兩電極14之假想連線的最短路 徑分散行進（如圖2中箭號所示），也因此，該發光二極體 1曰因為電流車父集中在此等區域而造成此等區域過熱，進而 導致該發光二極體丨的工作壽命縮短。 所以’目Θ的發光二極體需要加以改進，避免電流行 進過於集中，確保發光二極體的工作壽命。 【發明内容】 因此本發明之目的，即在提供一種可以避免電流過 於集中、確保工作壽命的發光二極體。 於是，本發明一種發光二極體包含一基材、至少一量 子單元、一電極，及一絕緣腾。 ,1284995 ' 該量子單元與該基材頂面相連接，並具有一第一型披 覆層、一第二型批覆層，及一在該第一、二型批覆層之間 • 的活性層，該第一、二型披覆層相對該活性層形成量子能 • 障而可以光電效應產生光。 該二電極彼此相間隔地與該量子單元電連接，可對該 $子單元提供電能而使電流分散通過該活性層，使該量子 單元產生光。 φ 該絕緣牆形成在該第一型披覆層中並位於該二電極之 間，且相對該第一型披覆層具有高電阻率，使電流分散通 過該活性層時的路徑增加及電荷密度均勻分配。 本發明的功效在於以形成在該量子單元中的絕緣牆使 電流分散路徑增加且電荷密度均勻分配，讓電流不致於過 • 度集中而造成局部區域過熱，確保發光二極體的工作壽命 Ο 【實施方式】 _ 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之一個較佳實施例的詳細說明中，將可 清楚的呈現。 在本發明被詳細描述之前，要注意的是，在以下的說 明内容中’類似的元件是以相同的編號來表示。 參閱圖3、圖4，本發明一種發光二極體2的一較佳實 施例，是包含一基材21、至少一磊晶形成在該基材21上的 量子單元22、一形成在該量子單元22頂面的透明導電層 23、二可提供電能的電極24，及一絕緣牆3。 7 1284995 • 該基材21是由晶格常數與該量子單元22相匹配的材 • 料構成’舉例來說，該量子單元22是屬氮化鎵系的半導體 • 材料時，該基材21則為易於磊晶的藍寶石。 • 該量子單元22自該基材頂面向上磊晶形成，具有一第 一型披覆層221 (cladding layer)、一第二型批覆層222，及 一在該第一、二型批覆層221、222之間的活性層223 ( active layer)，該第一、二型披覆層221、222相對該活性層 • 223形成量子能障而可以光電效應產生光；該第一、二型披 覆層221、222分別為n型彼覆層與p型披覆層；且，一般 為提昇發光效率，均會以複數量子單元為最佳設計，但在 本例與圖示中，為使說明清楚起見，僅以一量子單元22為 例說明。 該透明導電層23以可透光且可使電流分散均勻的材料 構成，例如銦錫氧化物（業界習稱ΙΤΟ )，而可使得以電極 24施加電能時，電流均勻地流通過該量子單元22的活性層 φ 223，而提昇發光效率。 該二電極24彼此相對遠離地與該量子單元22的第一 型彼覆層221以及該透明導電層23毆姆接觸，而可對該量 子單元22提供電能使該量子單元22產生光；較佳地，此 二電極24並非是與習知發光二極體1之二電極14之設置 位置一致，是彼此位於發光二極體1之一對角線的二角落 的對稱設計，而是以其中一電極24 (即圖示中呈圓形態樣 者）較遠離角落端之非對稱設計設置。 該絕緣牆3由該第一型披覆層221之一裸露於外界的 8 1284995 表面，以摻雜（dopped)高濃度的雜質向下，並呈一深度在 1000A〜70000A之間、厚度極薄的長方體態樣，形成在該第 一型披覆層221中並位於該二電極24之間，而相對該第一 型披覆層221具有高電阻率，使得電流是以沿自該絕緣牆3 相對遠離該二電極24之假想連線的兩端的較長路徑（如圖 中箭號所示）分散通過該活性層223，進而使得該量子單元 22的異質能階帶增加，穿隧效應減少，並可使得電荷密度 均勻分配，不致於過度集中於二電極24四周。 與習知發光二極體1相似地，當自該二電極24施加電 能時，電流經過該透明導電層23分散流通過該量子單元22 ，而使該量子單元22以光電效應產生光子，進而使該發光 一極體2向外發光。 而，雖然該第一型彼覆層221的電阻率遠小於第二型 披覆層222，造成當自該二電極24施加電能時電流會相對 車父集中於電極24的四周而未能均勻分散，但是因為電阻率 相對較高於該第一型披覆層221的絕緣牆3的阻絕，電流 會以沿自該絕緣牆3相對遠離該二電極24之假想連線的兩 、，而相對該二電極24之假想連線較為長的路徑分散通過 該活性層223,進而使得電荷密度均勻分配，不致於過度集 中於二電極24四周，使該發光二極體2不會因為電流集中 在特定區域，例如該二電極24四周及該二電極24假想連 線的周遭，而造成此等區域過熱，進而導致該發光二極體i 的工作壽命縮短。 在此要特別提出來說明的是，該絕緣牆3除了可如上 9 1284995 例所示，由第-型披覆層221裸露於外界的表面以推雜高 濃度雜質的方式向下形成之外，也可以如圖5所示，在磊 曰曰活性層223之前’在較接近於兩電極24假線連線之中央 位置，自第-型披覆層221的上表面向下摻雜形成深度 ΗΚ)0Α〜7_0Α之間、厚度極薄的長方體態樣，或是，如圖 6所不’以橫截面呈弧形態樣之絕緣牆3阻絕電流集中於兩 電極24假線連線之特定區域；由於此等關於該絕緣牆3之 位置、態樣等變化眾多，在此不再舉例贊述。 綜上述說明可知，本發明發光二極體2是以形成在第 一型披覆層221中且位於二電極24之間，而相對該第一型 披覆層221具有高電阻率的絕緣牆3，使得以電極24施加 電月b寺電机疋以沿自絕緣牆3相對遠離二電極μ之假想連 線兩端的較長路徑分散通過該活性層223，進而均勻分=電 荷密度增加，使電流不致於過度集中，同時使量子單元Μ 的異質能階帶增加’穿隨效應減少，確實可以改善習知發 光二極體1電流會相對較集中於電極14的四周而導致部分 區域過熱’進而縮短工作壽命的缺點，破實達到本發明的 創作目的。 ^淮以上所述者，僅為本發明之較佳實施例而已，當不 ，以此限定本發明實施之範圍’即大凡依本發明申請:利 範圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 【圖式簡單說明】 圖1是一剖視示意圖，說明一習知的發光二極體； 10 圖2是一俯視圖，輔助說明圖1之發光二極體； 圖3是一剖視示意圖，說明本發明發光二極體的一較 佳實施例； 圖4是一俯視圖，輔助說明圖3之發光二極體； 圖5是一俯視圖，說明一類似於圖3所示之發光二極 體，且該絕緣牆是在磊晶活性層223之前，自第一型彼覆 層221的上表面向下形成在較接近於兩電極24假線連線之 中央位置處；及 圖6是一俯視圖，說明一類似於圖3所示之發光二極 體，且該絕緣牆呈一弧形態樣。1284995 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a solid-state light-emitting element, and more particularly to a light-emitting diode. [Prior Art] Since the solid-state light-emitting element has the advantages of long life, low power consumption, small volume, low driving voltage, fast reaction rate, high recognition rate, etc., it is one of the new generation of light sources and types, especially the light-emitting diodes. For the application of everyday life. Referring to FIG. 1 and FIG. 2, in general, a light-emitting diode includes a substrate n, at least one crystal unit 12 formed on the substrate 11, and a transparent conductive layer 13 formed on a top surface of the quantum unit 12. And an electrode 14 for supplying electric energy. The substrate 11 is made of a material whose crystal constant is matched with the quantum unit. For example, the quantum unit 12 is a gallium nitride-based semiconductor material. The substrate 11 is a sapphire that is easy to epitaxial. The quantum unit 丨2 is epitaxially formed from the top surface of the substrate 11 and has a first cladding layer 121, a second cladding layer 122, and a first and second cladding layer. An active layer 123 between the 121 and the 122, the first and second type cladding layers i21 and i22 form a quantum energy barrier with respect to the active layer 123 to generate light by a photoelectric effect; the first and second types are covered by each other; The layers 121 and 122 are respectively an n-type cladding layer and a p-type cladding layer; and generally, in order to improve luminous efficiency, a plurality of subunits are optimally designed, but in this example and the illustration, for clarity of explanation For the sake of illustration, only one quantum unit 12 is illustrated as 5 1284995. The transparent conductive layer 13 is made of a material that can transmit light and can disperse the current, such as indium tin oxide (known in the industry as ITO), so that when the electrode 14 is applied with electric energy, a current flows uniformly through the quantum unit. The active layer 123 of 12 enhances luminous efficiency. The two electrodes 14 are in close contact with each other with the first-type cladding layer 121 of the quantum unit 12 and the transparent conductive layer 13, and electric energy can be supplied to the quantum unit 7L 12 to cause the quantum unit 12 to generate light. When electric energy is applied from the two electrodes 14, a current flows through the transparent conductive layer 13 through the quantum unit 12, and the quantum unit a generates photons by photoelectric effect, thereby causing the light-emitting diode 1 to emit light outward. Since the resistivity of the first type cladding layer 121 is much smaller than that of the second type cladding layer 122, when electric energy is applied from the two electrodes 14, the current is relatively concentrated on the periphery of the electrode 14, and the imaginary of the two electrodes 14 The shortest path of the connection is dispersed (as indicated by the arrow in Fig. 2), and therefore, the light-emitting diode 1 is caused by the current carrier being concentrated in such areas, causing the area to overheat, thereby causing the light-emitting diode The working life of the body is shortened. Therefore, the 'light-emitting diodes' that need to be improved need to be improved to avoid excessive current concentration and ensure the working life of the light-emitting diodes. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a light-emitting diode that can avoid current from being concentrated and ensuring a working life. Thus, a light-emitting diode of the present invention comprises a substrate, at least one quantum unit, an electrode, and an insulating layer. , 1284995 'the quantum unit is connected to the top surface of the substrate, and has a first type of cladding layer, a second type of cladding layer, and an active layer between the first and second type of cladding layers, The first and second type cladding layers form quantum energy barriers with respect to the active layer and can generate light by photoelectric effect. The two electrodes are electrically connected to the quantum unit at intervals, and the subunit can be supplied with electrical energy to disperse current through the active layer to cause the quantum unit to generate light. φ The insulating wall is formed in the first type of cladding layer and located between the two electrodes, and has a high resistivity with respect to the first type of cladding layer, and an increase in path and charge density when current is dispersed through the active layer Evenly distributed. The effect of the invention is that the insulating wall formed in the quantum unit increases the current dispersion path and uniformly distributes the charge density, so that the current does not concentrate excessively, causing local area overheating, and ensuring the working life of the light emitting diode. The above and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the preferred embodiments. Before the present invention is described in detail, it is to be noted that in the following description, similar elements are denoted by the same reference numerals. Referring to FIG. 3 and FIG. 4, a preferred embodiment of a light-emitting diode 2 of the present invention comprises a substrate 21, at least one epitaxially formed quantum unit 22 on the substrate 21, and a quantum device 22 formed thereon. A transparent conductive layer 23 on the top surface of the unit 22, two electrodes 24 for supplying electrical energy, and an insulating wall 3 are provided. 7 1284995 • The substrate 21 is composed of a material having a lattice constant matched to the quantum unit 22. For example, when the quantum unit 22 is a gallium nitride-based semiconductor material, the substrate 21 is A sapphire for easy epitaxial. • The quantum unit 22 is epitaxially formed from the top surface of the substrate, having a first cladding layer 221, a second cladding layer 222, and a first and second cladding layer 221 An active layer 223 between the 222, the first and second type cladding layers 221, 222 form a quantum energy barrier with respect to the active layer 223, and can generate light by a photoelectric effect; the first type and the second type are covered. The layers 221 and 222 are respectively an n-type cladding layer and a p-type cladding layer; and generally, in order to improve luminous efficiency, a plurality of sub-units are optimally designed, but in this example and the illustration, in order to make the explanation clear For example, only one quantum unit 22 is taken as an example. The transparent conductive layer 23 is made of a material that can transmit light and has a uniform current dispersion, such as indium tin oxide (known in the industry), so that when the electrode 24 is applied with electric energy, a current flows uniformly through the quantum unit 22 . The active layer φ 223 improves the luminous efficiency. The two electrodes 24 are in contact with each other and the first type of the second layer 221 of the quantum unit 22 and the transparent conductive layer 23, and the quantum unit 22 can be powered to generate light. The two electrodes 24 are not in the same position as the two electrodes 14 of the conventional light-emitting diode 1, and are symmetrically located at two corners of one diagonal of the light-emitting diode 1, but one of them. The electrode 24 (i.e., the circular shape in the illustration) is disposed asymmetrically away from the corner end. The insulating wall 3 is exposed to the outside surface of the 8 1284995 by one of the first type of cladding layers 221, and is doped with a high concentration of impurities downward, and has a depth between 1000A and 70,000A, and the thickness is extremely thin. The rectangular parallelepiped is formed in the first type of cladding layer 221 and located between the two electrodes 24, and has a high resistivity relative to the first type of cladding layer 221, so that the current is along the insulating wall 3 A longer path (shown by an arrow in the figure) that is relatively far from the both ends of the imaginary connection of the two electrodes 24 is dispersed through the active layer 223, thereby increasing the heterogeneous energy band of the quantum unit 22 and reducing the tunneling effect. The charge density can be evenly distributed without being excessively concentrated around the two electrodes 24. Similar to the conventional light-emitting diode 1, when electric energy is applied from the two electrodes 24, a current flows through the transparent conductive layer 23 through the quantum unit 22, causing the quantum unit 22 to generate photons by photoelectric effect, thereby The light-emitting body 2 emits light outward. However, although the resistivity of the first type of cladding layer 221 is much smaller than that of the second type cladding layer 222, the current is concentrated on the periphery of the electrode 24 relative to the vehicle owner when the electric energy is applied from the two electrodes 24, and is not uniformly dispersed. However, because the resistivity is relatively higher than the blocking of the insulating wall 3 of the first type of cladding layer 221, the current will be two along the imaginary connection from the insulating wall 3 away from the two electrodes 24, and the opposite The longer path of the imaginary connection of the two electrodes 24 is dispersed through the active layer 223, so that the charge density is evenly distributed, so as not to be excessively concentrated around the two electrodes 24, so that the light-emitting diode 2 is not concentrated in a specific region due to current. For example, the circumference of the two electrodes 24 and the surroundings of the imaginary connection of the two electrodes 24 cause overheating of the regions, thereby causing the working life of the light-emitting diodes i to be shortened. In particular, it is to be noted that the insulating wall 3 can be formed downward by the first-type cladding layer 221 exposed on the surface of the outside to push up high-concentration impurities, as shown in the above example of 12 1284995. Alternatively, as shown in FIG. 5, before the extension active layer 223, the upper surface of the first-type cladding layer 221 is doped down to form a depth 中央 at a position closer to the line connecting the false lines of the two electrodes 24. ) a rectangular parallelepiped shape between 0Α and 7_0Α, which is extremely thin, or, as shown in Fig. 6, the insulating wall 3 having an arc shape in cross section is concentrated in a specific region of the connection line of the two electrodes 24; Since the position, the state, and the like of the insulating wall 3 are numerous, the details are not described herein. As can be seen from the above description, the light-emitting diode 2 of the present invention is an insulating wall 3 which is formed in the first type cladding layer 221 and is located between the two electrodes 24 and has a high resistivity with respect to the first type cladding layer 221. So that the electrode 24 is applied by the electrode 24 to disperse through the active layer 223 along a longer path from the opposite ends of the insulating wall 3 from the imaginary connection of the two electrodes μ, thereby uniformly dividing the charge density to cause current It is not excessively concentrated, and at the same time, the heterogeneous energy band of the quantum unit 增加 is increased, and the wear-through effect is reduced. It is indeed possible to improve that the current of the light-emitting diode 1 is relatively concentrated on the periphery of the electrode 14 and causes partial overheating, thereby shortening. The shortcomings of the working life achieve the purpose of the invention. The above is only the preferred embodiment of the present invention, and if not, the scope of the present invention is defined as the scope of the present invention. And modifications are still within the scope of the invention patent. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a conventional light-emitting diode; FIG. 2 is a top view for explaining the light-emitting diode of FIG. 1; FIG. 3 is a cross-sectional view showing FIG. 4 is a top view of the light emitting diode of FIG. 3; FIG. 5 is a top view showing a light emitting diode similar to that shown in FIG. The insulating wall is formed from the upper surface of the first type of cladding layer 221 downward at a central position closer to the false line connecting the two electrodes 24 before the epitaxial active layer 223; and FIG. 6 is a top view illustrating A light-emitting diode similar to that shown in FIG. 3, and the insulating wall has an arc shape.
1284995 11 1284995 【主要元件符號說明】 1 發光二極體 21 基材 11 基材 22 量子單元 12 量子單元 221 第一型批覆層 121 第一型批覆層 222 第二型批覆層 122 第二型批覆層 223 活性層 123 活性層 23 透明導電層 13 透明導電層 24 電極 14 電極 3 絕緣牆 2 發光二極體 121284995 11 1284995 [Explanation of main components] 1 Luminous diode 21 Substrate 11 Substrate 22 Quantum unit 12 Quantum unit 221 First type cladding layer 121 First type cladding layer 222 Second type cladding layer 122 Second type cladding layer 223 active layer 123 active layer 23 transparent conductive layer 13 transparent conductive layer 24 electrode 14 electrode 3 insulating wall 2 light emitting diode 12