A semiconductor light emitting device having a carrier concentration matching layer

Abstract

This invention relates to a semiconductor light-emitting element having a carrier concentration matching layer, comprising, from bottom to top, a substrate, a first n-type semiconductor, a second n-type semiconductor, a third n-type semiconductor, a first quantum well, a second quantum well, an electron blocking layer, and a p-type semiconductor. A first carrier concentration matching layer is located between the first and second n-type semiconductors; a second carrier concentration matching layer is located between the second and third n-type semiconductors; a third carrier concentration matching layer is located between the first and second quantum wells; and a fourth carrier concentration matching layer is located between the second quantum well and the electron blocking layer. The matching degree of electron and hole concentrations injected into the first and second quantum wells is controlled, increasing the electron-hole matching degree of the second quantum well from approximately 70% to over 90%, thereby improving the electron-hole recombination efficiency of the second quantum well and increasing the external quantum efficiency (EQE) of the semiconductor light-emitting element from approximately 60% to approximately 75%.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronics technology, and more particularly to a semiconductor light-emitting element having a carrier concentration matching layer. Background Technology

[0002] Semiconductor components, especially semiconductor light-emitting components, have a wide range of adjustable wavelengths, high luminous efficiency, energy saving and environmental protection, a long lifespan of over 100,000 hours, small size, multiple application scenarios, and strong design flexibility. As a result, they have gradually replaced incandescent and fluorescent lamps, becoming the light source for ordinary household lighting and are widely used in new scenarios, such as indoor high-resolution displays, outdoor displays, Mini-LED, Micro-LED, mobile phone TV backlights, backlighting, streetlights, car headlights, daytime running lights, car interior ambient lighting, flashlights, and other application areas. Traditional nitride semiconductors are grown on sapphire substrates, resulting in large lattice and thermal mismatches, leading to high defect density and polarization effects, which reduce the luminous efficiency of semiconductor light-emitting devices. Simultaneously, the hole ionization efficiency of traditional nitride semiconductors is much lower than that of electron ionization, resulting in a hole concentration that is more than an order of magnitude lower than the electron concentration. Excess electrons overflow from the multiple quantum wells to the second conductivity type semiconductor, causing nonradiative recombination. The low hole ionization efficiency makes it difficult for holes in the second conductivity type semiconductor to be effectively injected into the multiple quantum wells, leading to low luminous efficiency. Furthermore, the non-centrosymmetric structure of nitride semiconductors generates strong spontaneous polarization along the c-axis, which, combined with the piezoelectric polarization effect of lattice mismatch, forms an intrinsic polarization field. This intrinsic polarization field, along the 001 direction, causes a strong quantum confinement Stark effect in the multiple quantum well layer, resulting in band tilt and spatial separation of the electron-hole wavefunction, reducing the radiative recombination efficiency of electrons and holes. Summary of the Invention

[0003] This invention provides a semiconductor light-emitting element with a carrier concentration matching layer, comprising, from bottom to top, a substrate, a first type semiconductor, a second type semiconductor, a third type semiconductor, a first quantum well, a second quantum well, an electron blocking layer, and a fourth type semiconductor. A first carrier concentration matching layer is located between the first and second type semiconductors; a second carrier concentration matching layer is located between the second and third type semiconductors; a third carrier concentration matching layer is located between the first and second quantum wells; and a fourth carrier concentration matching layer is located between the second quantum well and the electron blocking layer. The first, second, third, and fourth carrier concentration matching layers together constitute the carrier concentration matching layer.

[0004] Furthermore, the first carrier concentration matching layer is any one or any combination of AlGaN, AlInGaN, or AlIN materials, with a thickness of 5~100nm; the Si doping concentration of the first carrier concentration matching layer has a V-shaped distribution, and the Si doping concentration in the first carrier concentration matching layer first decreases and then increases towards the first n-type semiconductor direction. The Si doping concentration decreases at an angle δ: 80°≥δ≥35°, and the Si doping concentration increases at an angle φ: 60°≥φ≥15°, where δ≥φ.

[0005] Furthermore, the second carrier concentration matching layer is any one or any combination of AlGaN, AlInGaN, or AlIN materials, with a thickness of 5~100nm; the Si doping concentration of the second carrier concentration matching layer exhibits a double-step decreasing trend towards the third n-type semiconductor direction, including a first decreasing step and a second decreasing step; the Si doping concentration decreasing angle of the first decreasing step is γ: 80°≥γ≥20°, and the Si doping concentration decreasing angle of the second decreasing step is θ: 80°≥θ≥30°, where θ≥γ.

[0006] Furthermore, the third carrier concentration matching layer is any one or any combination of GaN or InGaN, with a thickness of 2~50nm; the Si doping concentration of the third carrier concentration matching layer decreases towards the first quantum well, with a Si doping concentration decrease angle of β: 80°≥β≥20°, and the Si doping concentration exhibits an inverted V-shape, with the peak position of the inverted V-shaped Si doping concentration being close to the valley position of the In composition, with a position deviation of + / -5nm.

[0007] Furthermore, the fourth carrier concentration matching layer 102d is any one or any combination of AlGaN, AlInGaN, GaN, or AlInN, with a thickness of 1~30nm; the Mg doping concentration of the fourth carrier concentration matching layer 102d decreases towards the second quantum well, and the Mg doping concentration decreases by an angle α: 80°≥α≥30°.

[0008] Furthermore, the carrier concentration matching layer α≥θ≥γ≥β≥δ≥φ controls the matching degree of electron and hole concentrations injected into the first and second quantum wells, thereby increasing the matching degree of electrons and holes in the second quantum well from about 70% to over 90%, and improving the electron-hole recombination efficiency of the second quantum well.

[0009] Furthermore, the Si doping concentration in the first carrier concentration matching layer towards the first n-type semiconductor ranges from 1E19 to 1E20 cm⁻¹. -3 Decreased to 1E18~1E19cm -3 Further rise to 5E18~5E19cm -3The Si doping concentration of the second carrier concentration matching layer to the third n-type semiconductor first increases from 1E19 to 1E20 cm⁻¹. -3 Decreased to 5E18~5E19cm -3 It then dropped to 5E17~5E18cm -3 The Si doping concentration in the third carrier concentration matching layer towards the first quantum well ranges from 1E18 to 1E19 cm⁻¹. -3 Decreased to 5E17~5E18cm -3 The Mg doping concentration in the fourth carrier concentration matching layer towards the second quantum well ranges from 1E19 to 5E20 cm⁻¹. -3 Decreased to 1E15~5E18cm -3 .

[0010] Furthermore, both the first and second quantum wells are periodic structures composed of well layers and barrier layers, with period numbers a: 3≤a≤15 and b: 5≤b≤15, respectively; the thickness of the well layer of the first quantum well is c: 10≤c≤50 angstroms, and the thickness of the barrier layer is d: 10≤c≤200 angstroms; the thickness of the well layer of the second quantum well is e: 15≤e≤60 angstroms, and the thickness of the barrier layer is f: 20≤f≤120 angstroms.

[0011] Furthermore, the first n-type semiconductor, the second n-type semiconductor, the third n-type semiconductor, the first quantum well, the second quantum well electron blocking layer, and the p-type semiconductor include any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP.

[0012] Furthermore, the substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, and sapphire / SiN composite substrate. x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

[0013] Compared to existing technologies: a first carrier concentration matching layer exists between the first n-type semiconductor and the second n-type semiconductor; a second carrier concentration matching layer exists between the second n-type semiconductor and the third n-type semiconductor; a third carrier concentration matching layer exists between the first quantum well and the second quantum well; and a fourth carrier concentration matching layer exists between the second quantum well and the electron blocking layer. The first, second, third, and fourth carrier concentration matching layers together constitute the carrier concentration matching layer. The α≥θ≥γ≥β≥δ≥φ of the carrier concentration matching layer controls the matching degree of electron and hole concentrations injected into the first and second quantum wells, thereby increasing the matching degree of electrons and holes in the second quantum well from about 70% to over 90%, improving the electron-hole recombination efficiency of the second quantum well, and thus increasing the external quantum efficiency (EQE) of the semiconductor light-emitting element from about 60% to about 75%. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a semiconductor light-emitting element according to an embodiment of the present invention;

[0015] Figure 2 This is a SIMS secondary ion mass spectrum of the semiconductor light-emitting element according to an embodiment of the present invention;

[0016] Figure 3 This is a partial SIMS secondary ion mass spectrum of the semiconductor light-emitting element according to an embodiment of the present invention;

[0017] Figure 4 This is a TEM transmission electron microscope image of a partial structure of the semiconductor light-emitting element according to an embodiment of the present invention;

[0018] Figure 5 This is a TEM transmission electron microscope image of a partial structure of the semiconductor light-emitting element according to an embodiment of the present invention;

[0019] The reference numerals for the accompanying drawings in the specification are as follows:

[0020] 100: Substrate; 101: First n-type semiconductor; 102: Carrier concentration matching layer; 102a: First carrier concentration matching layer; 102b: Second carrier concentration matching layer; 102c: Third carrier concentration matching layer; 102d: Fourth carrier concentration matching layer; 103: Second n-type semiconductor; 104: Third n-type semiconductor; 105: First quantum well; 106: Second quantum well; 107: Electron blocking layer; 108: P-type semiconductor. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please refer to Figures 1-5 This is a schematic diagram of a semiconductor laser according to an embodiment of the present invention. A semiconductor light-emitting element with a carrier concentration matching layer includes, from bottom to top, a substrate 100, a first n-type semiconductor 101, a second n-type semiconductor 103, a third n-type semiconductor 104, a first quantum well 105, a second quantum well 106, an electron blocking layer 107, and a p-type semiconductor 108. A first carrier concentration matching layer 102a is located between the first n-type semiconductor 101 and the second n-type semiconductor 103. A second carrier concentration matching layer 102b is provided between the body 103 and the third n-type semiconductor 104, a third carrier concentration matching layer 102c is provided between the first quantum well 105 and the second quantum well 106, and a fourth carrier concentration matching layer 102d is provided between the second quantum well 106 and the electron blocking layer 107; the first carrier concentration matching layer 102a, the second carrier concentration matching layer 102b, the third carrier concentration matching layer 102c and the fourth carrier concentration matching layer 102d together constitute a carrier concentration matching layer.

[0023] In this embodiment, the first carrier concentration matching layer 102a is any one or any combination of AlGaN, AlInGaN, or AlIN materials, with a thickness of 5~100nm; the Si doping concentration of the first carrier concentration matching layer 102a has a V-shaped distribution, and the Si doping concentration of the first carrier concentration matching layer 102a towards the first n-type semiconductor 101 first decreases and then increases, with the Si doping concentration decreasing angle δ: 80°≥δ≥35°, and the Si doping concentration increasing angle φ: 60°≥φ≥15°, where δ≥φ.

[0024] In this embodiment, the second carrier concentration matching layer 102b is any one or any combination of AlGaN, AlInGaN, or AlIN materials, with a thickness of 5~100nm; the Si doping concentration of the second carrier concentration matching layer 102b exhibits a double-step decreasing trend towards the third n-type semiconductor 104, including a first decreasing step and a second decreasing step; the Si doping concentration decreasing angle of the first decreasing step is γ: 80°≥γ≥20°, and the Si doping concentration decreasing angle of the second decreasing step is θ: 80°≥θ≥30°, where θ≥γ.

[0025] In this embodiment, the third carrier concentration matching layer 102c is any one or any combination of GaN or InGaN, with a thickness of 2~50nm; the Si doping concentration of the third carrier concentration matching layer 102c decreases towards the first quantum well 105, the Si doping concentration decreases at an angle β: 80°≥β≥20°, and the Si doping concentration exhibits an inverted V-shape, with the peak position of the inverted V-shaped Si doping concentration being close to the valley position of the In composition, with a position deviation of + / -5nm.

[0026] In this embodiment, the fourth carrier concentration matching layer 102d is any one or any combination of AlGaN, AlInGaN, GaN, or AlInN, with a thickness of 1~30nm; the Mg doping concentration of the fourth carrier concentration matching layer 102d decreases towards the second quantum well 106, and the Mg doping concentration decreases by an angle α: 80°≥α≥30°.

[0027] In this embodiment, the carrier concentration matching layer α≥θ≥γ≥β≥δ≥φ controls the matching degree of electron and hole concentrations injected into the first quantum well 105 and the second quantum well 106, thereby increasing the matching degree of electrons and holes in the second quantum well 106 from about 70% to more than 90%, and improving the electron and hole recombination efficiency of the second quantum well 106.

[0028] In this embodiment, the Si doping concentration of the first carrier concentration matching layer 102a toward the first n-type semiconductor 101 is from 1E19 to 1E20 cm⁻¹. -3 Decreased to 1E18~1E19cm -3 Further rise to 5E18~5E19cm -3 The Si doping concentration of the second carrier concentration matching layer 102b to the third n-type semiconductor 104 first increases from 1E19 to 1E20 cm⁻¹. -3 Decreased to 5E18~5E19cm -3 It then dropped to 5E17~5E18cm -3 The Si doping concentration in the third carrier concentration matching layer 102b towards the first quantum well 105 ranges from 1E18 to 1E19 cm⁻¹. -3 Decreased to 5E17~5E18cm -3 The Mg doping concentration in the fourth carrier concentration matching layer 102d towards the second quantum well 106 ranges from 1E19 to 5E20 cm⁻¹. -3 Decreased to 1E15~5E18cm -3 .

[0029] In this embodiment, both the first quantum well 105 and the second quantum well 106 are periodic structures composed of well layers and barrier layers, with period numbers a: 3≤a≤15 and b: 5≤b≤15, respectively; the thickness of the well layer of the first quantum well 105 is c: 10≤c≤50 angstroms, and the thickness of the barrier layer is d: 10≤c≤200 angstroms; the thickness of the well layer of the second quantum well 106 is e: 15≤e≤60 angstroms, and the thickness of the barrier layer is f: 20≤f≤120 angstroms.

[0030] In this embodiment, the first n-type semiconductor 101, the second n-type semiconductor 103, the third n-type semiconductor 104, the first quantum well 105, the second quantum well 106, the electron blocking layer 107, and the p-type semiconductor 108 include any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP.

[0031] In this embodiment, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, and sapphire / SiN composite substrate. x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

[0032]

[0033] A first carrier concentration matching layer is provided between the first n-type semiconductor and the second n-type semiconductor; a second carrier concentration matching layer is provided between the second n-type semiconductor and the third n-type semiconductor; a third carrier concentration matching layer is provided between the first quantum well and the second quantum well; and a fourth carrier concentration matching layer is provided between the second quantum well and the electron blocking layer. The first, second, third, and fourth carrier concentration matching layers together constitute the carrier concentration matching layer. The α≥θ≥γ≥β≥δ≥φ of the carrier concentration matching layer controls the matching degree of electron and hole concentrations injected into the first and second quantum wells, thereby increasing the matching degree of electrons and holes in the second quantum well from about 70% to over 90%, improving the electron-hole recombination efficiency of the second quantum well, and thus increasing the external quantum efficiency (EQE) of the semiconductor light-emitting element from about 60% to about 75%.

[0034] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A semiconductor light-emitting element having a carrier concentration matching layer, comprising, from bottom to top, a substrate (100), a first n-type semiconductor (101), a second n-type semiconductor (103), a third n-type semiconductor (104), a first quantum well (105), a second quantum well (106), an electron blocking layer (107), and a p-type semiconductor (108), characterized in that, A first carrier concentration matching layer (102a) is provided between the first n-type semiconductor (101) and the second n-type semiconductor (103); a second carrier concentration matching layer (102b) is provided between the second n-type semiconductor (103) and the third n-type semiconductor (104); a third carrier concentration matching layer (102c) is provided between the first quantum well (105) and the second quantum well (106); and a fourth carrier concentration matching layer (102d) is provided between the second quantum well (106) and the electron blocking layer (107). The first carrier concentration matching layer (102a), the second carrier concentration matching layer (102b), the third carrier concentration matching layer (102c), and the fourth carrier concentration matching layer (102d) together constitute a carrier concentration matching layer. The first carrier concentration matching layer (102a) is any one or any combination of AlGaN, AlInGaN, or AlIN materials, with a thickness of 5~100nm; the Si doping concentration of the first carrier concentration matching layer (102a) has a V-shaped distribution, and the Si doping concentration in the first carrier concentration matching layer (102a) towards the first n-type semiconductor (101) first decreases and then increases, with the Si doping concentration decreasing angle δ: 80°≥δ≥35°, and the Si doping concentration increasing angle φ: 60°≥φ≥15°, where δ≥φ; The second carrier concentration matching layer (102b) is any one or any combination of AlGaN, AlInGaN, or AlIN materials, with a thickness of 5~100nm; the Si doping concentration of the second carrier concentration matching layer (102b) decreases in a double-step manner towards the third n-type semiconductor (104), including a first decreasing step and a second decreasing step; the Si doping concentration decrease angle of the first decreasing step is γ: 80°≥γ≥20°, and the Si doping concentration decrease angle of the second decreasing step is θ: 80°≥θ≥30°, where θ≥γ; The third carrier concentration matching layer (102c) is any one or any combination of GaN or InGaN, with a thickness of 2~50nm; the Si doping concentration of the third carrier concentration matching layer (102c) decreases towards the first quantum well (105), with a Si doping concentration decrease angle of β: 80°≥β≥20°, and the Si doping concentration exhibits an inverted V-shape, with the peak position of the inverted V-shaped Si doping concentration being close to the valley position of the In composition, with a position deviation of + / -5nm; The fourth carrier concentration matching layer (102d) is any one or any combination of AlGaN, AlInGaN, GaN, or AlInN, with a thickness of 1~30nm; the Mg doping concentration of the fourth carrier concentration matching layer (102d) decreases towards the second quantum well (106), and the angle of decrease in Mg doping concentration is α: 80°≥α≥30°; The carrier concentration matching layer α≥θ≥γ≥β≥δ≥φ controls the matching degree of electron and hole concentrations injected into the first quantum well (105) and the second quantum well (106), thereby increasing the matching degree of electrons and holes in the second quantum well (106) from about 70% to more than 90%, and improving the electron and hole recombination efficiency of the second quantum well (106).

2. A semiconductor light-emitting element having a carrier concentration matching layer as described in claim 1, characterized in that, The Si doping concentration in the first carrier concentration matching layer (102a) towards the first n-type semiconductor (101) ranges from 1E19 to 1E20 cm⁻¹. -3 Decreased to 1E18~1E19cm -3 Further rise to 5E18~5E19cm -3 The Si doping concentration in the second carrier concentration matching layer (102b) and the third n-type semiconductor (104) first increases from 1E19 to 1E20 cm⁻¹. -3 Decreased to 5E18~5E19cm -3 It then dropped to 5E17~5E18cm -3 The Si doping concentration in the third carrier concentration matching layer (102c) towards the first quantum well (105) ranges from 1E18 to 1E19 cm⁻¹. -3 Decreased to 5E17~5E18cm -3 The Mg doping concentration from the fourth carrier concentration matching layer (102d) toward the second quantum well (106) ranges from 1E19 to 5E20 cm⁻¹. -3 Decreased to 1E15~5E18cm -3 .

3. A semiconductor light-emitting element having a carrier concentration matching layer as described in claim 1, characterized in that, The first quantum well (105) and the second quantum well (106) are both periodic structures composed of well layers and barrier layers, with period numbers a: 3≤a≤15 and b: 5≤b≤15, respectively; the thickness of the well layer of the first quantum well (105) is c: 10≤c≤50 angstroms, and the thickness of the barrier layer is d: 10≤c≤200 angstroms; the thickness of the well layer of the second quantum well (106) is e: 15≤e≤60 angstroms, and the thickness of the barrier layer is f: 20≤f≤120 angstroms.

4. A semiconductor light-emitting element having a carrier concentration matching layer as described in claim 1, characterized in that, The first n-type semiconductor (101), the second n-type semiconductor (103), the third n-type semiconductor (104), the first quantum well (105), the second quantum well (106), the electron blocking layer (107), and the p-type semiconductor (108) include any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP.

5. A semiconductor light-emitting element having a carrier concentration matching layer as described in claim 1, characterized in that, The substrate (100) includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, and sapphire / SiN composite substrate. x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

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