Preparation method of rare earth doped GaN nanofilm

Abstract

The present invention discloses a method for preparing a rare-earth-doped GaN nanofilm, comprising the following steps: Step 1: A gallium metal evaporation pool and a rare-earth europium metal evaporation pool are respectively provided in the first and third air inlet channels of a reactor, and the substrate is provided at the bottom of the reactor; Step 2: A mixture of nitrogen and hydrogen as a carrier gas mixed with ammonia is introduced into the reactor through the second air inlet channel, and hydrogen chloride is flowed as a reaction gas through the first and third air inlet channels respectively provided with the gallium metal evaporation pools and the rare-earth europium metal evaporation pools, thereby forming a europium-doped GaN single crystal film on the substrate; Step 3: The europium-doped GaN single crystal film obtained in Step 2 is placed in a furnace for annealing under the following annealing conditions: nitrogen or ammonia, an annealing temperature of 1000-1200°C, and an annealing time of 0.5-4 hours. The GaN nanofilm obtained by the preparation method of the present invention is uniformly doped with rare earth ions and can be integrated into the GaN crystal lattice.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductors, and in particular to a method for preparing a rare earth-doped GaN nanofilm. Background Art

[0002] GaN materials have broad application prospects in fields such as microelectronics and optoelectronics, and their research and application are currently at the forefront and hot topic of global semiconductor research. Along with semiconductor materials such as SiC and diamond, they are considered the third generation of semiconductor materials, following the first generation of Ge and Si semiconductor materials and the second generation of GaAs and InP compound semiconductor materials. Currently, GaN-based light-emitting devices are widely used in lighting, display, and other fields. In 2014, the inventor of GaN-based blue LEDs was awarded the Nobel Prize in Physics. GaN materials also have important applications in power electronics and microwave and radio frequency fields.

[0003] Rare earth ion doped GaN material systems and light-emitting devices have shown good application prospects and huge development potential in the fields of flat panel displays, optical communications, solid-state lasers, ferromagnetism, etc. At present, the nanostructures of rare earth ion doped GaN materials are prepared by solution chemistry methods. For example, M. Nyk et al. mixed a certain proportion of Ga2O3, Er2O3, and Yb2O3, dissolved them in hot concentrated nitric acid, and then evaporated them to dryness. The obtained powder was placed in a corundum crucible and heated at 800℃ in an air atmosphere to decompose to obtain Er and Yb co-doped Ga2O3 powder. Then, Er and Yb co-doped GaN nanopowders were obtained by heating at 850℃ in an ammonia atmosphere (see M. Nyk, et al. Red up-conversion emission from nanocrystalline GaN powders co-doped with Er 3+ and Yb 3+ , Optical Materials, 2009, 31: 800-804).

[0004] The existing technology has the following technical defects: uneven doping of rare earth ions and difficulty in entering the GaN lattice, which leads to high material defect density and uneven luminescence. Summary of the Invention

[0005] The present invention aims to provide a method for preparing rare earth-doped GaN nanofilms, wherein the rare earth ions in the obtained rare earth-doped GaN nanofilms are uniformly doped and can be incorporated into the GaN lattice, thereby reducing defect density and improving luminescence uniformity.

[0006] To achieve the above objectives, the present invention adopts a technical solution: a method for preparing a rare earth-doped GaN nanofilm, the method based on a reactor having a first air inlet channel, a second air inlet channel, and a third air inlet channel arranged in a vertical direction on one side of the reactor, and an exhaust channel on the other side, wherein a substrate is located between the first air inlet channel, the second air inlet channel, the third air inlet channel, and the exhaust channel;

[0007] The following steps are involved:

[0008] Step 1: A gallium metal evaporation pool and a rare earth europium metal evaporation pool are respectively provided in the first air inlet channel and the third air inlet channel of the reactor, and the substrate is provided at the bottom of the reactor;

[0009] Step 2: A mixture of nitrogen and hydrogen as a carrier gas mixed with ammonia enters the reactor through the second gas inlet channel, and hydrogen chloride as a reaction gas flows through the first gas inlet channel and the third gas inlet channel respectively, where a gallium metal evaporation pool and a rare earth europium metal evaporation pool are provided, thereby forming a europium-doped GaN single crystal thin film on the substrate; the temperature of the gallium metal evaporation pool is 850-900°C, and the temperature of the rare earth europium metal evaporation pool is 600-1000°C;

[0010] Step 3: Place the europium-doped GaN single crystal film obtained in step 2 into a furnace for annealing. The annealing conditions are: nitrogen or ammonia, annealing temperature of 1000-1200° C., and annealing time of 0.5-4 h.

[0011] The further improved scheme in the above technical scheme is as follows:

[0012] 1. In the above solution, the rare earth europium metal evaporation pool is arranged above the gallium metal evaporation pool.

[0013] 2. In the above solution, the growth rate of the europium-doped GaN single crystal thin film on the substrate is controlled at 60 to 120 μm / h.

[0014] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0015] The method for preparing the rare earth-doped GaN nanofilm of the present invention can achieve uniform rare earth ion doping in the GaN nanofilm and enable the rare earth ions to enter the GaN lattice, thereby reducing defect density and improving luminescence uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attachment Figure 1 Schematic diagram of the reactor structure of the method for preparing GaN nanofilm of the present invention;

[0017] Attachment Figure 2 This is a SEM microscopic photograph of the GaN nanofilm obtained by the preparation method of the present invention.

[0018] In the above figures: 1. Reactor; 2. First air inlet channel; 3. Second air inlet channel; 4. Third air inlet channel; 5. Exhaust channel; 6. Gallium metal evaporation pool; 7. Rare earth europium metal evaporation pool; 8. Substrate. DETAILED DESCRIPTION

[0019] Example: A method for preparing rare earth doped GaN nanofilm, as shown in the attached Figure 1 As shown, the preparation method is based on a reactor 1, which has a first gas inlet channel 2, a second gas inlet channel 3, and a third gas inlet channel 4 arranged in sequence in the vertical direction on one side of the reactor 1, and an exhaust channel 5 on the other side, and a substrate 8 is located between the first gas inlet channel 2, the second gas inlet channel 3, the third gas inlet channel 4 and the exhaust channel 5;

[0020] The following steps are involved:

[0021] Step 1: A gallium metal evaporation pool 6 and a rare earth europium metal evaporation pool 7 are respectively provided in the first air inlet channel 2 and the third air inlet channel 4 of the reactor 1, and the substrate 8 is provided at the bottom of the reactor 1;

[0022] Step 2: A mixture of nitrogen and hydrogen as a carrier gas mixed with ammonia enters the reactor 1 through the second gas inlet channel 3, and hydrogen chloride as a reaction gas flows through the first gas inlet channel 2 and the third gas inlet channel 4, which are respectively provided with a gallium metal evaporation pool 6 and a rare earth europium metal evaporation pool 7, thereby forming a europium-doped GaN single crystal thin film on the substrate 8; the temperature of the gallium metal evaporation pool 6 is 860°C, and the temperature of the rare earth europium metal evaporation pool 7 is 700°C;

[0023] Step 3: Place the europium-doped GaN single crystal film obtained in step 2 into a furnace for annealing. The annealing conditions are: nitrogen or ammonia, annealing temperature is 1100° C., and annealing time is 0.5 h.

[0024] The rare earth europium metal evaporation pool 7 is disposed above the gallium metal evaporation pool 6 .

[0025] The growth rate of the europium-doped GaN single crystal thin film on the substrate 8 is controlled at 80 μm / h.

[0026] The rare earth doped GaN nanofilm obtained in this embodiment has a microscopic photograph as shown in FIG. Figure 2 As shown, nanostructures with hexagonal features can be observed, with a size of less than 1 μm.

[0027] When the above-mentioned method for preparing rare earth-doped GaN nanofilm is adopted, the rare earth ions in the GaN nanofilm are uniformly doped and can enter the GaN lattice, thereby reducing the defect density and improving the luminescence uniformity.

[0028] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a rare earth-doped GaN nanofilm, characterized in that: The preparation method is based on a reactor (1), wherein one side of the reactor (1) is provided with a first air inlet channel (2), a second air inlet channel (3), and a third air inlet channel (4) in sequence in a vertical direction, and the other side is provided with an exhaust channel (5), and a substrate (8) is located between the first air inlet channel (2), the second air inlet channel (3), the third air inlet channel (4), and the exhaust channel (5); The following steps are involved: Step 1: A gallium metal evaporation pool (6) and a rare earth europium metal evaporation pool (7) are respectively provided in the first air inlet channel (2) and the third air inlet channel (4) in the reactor (1), and the substrate (8) is provided at the bottom of the reactor (1); Step 2: A mixed gas of nitrogen and hydrogen as a carrier gas mixed with ammonia enters the reactor (1) from the second gas inlet channel (3), and hydrogen chloride as a reaction gas flows through the first gas inlet channel (2) and the third gas inlet channel (4) respectively provided with a gallium metal evaporation pool (6) and a rare earth europium metal evaporation pool (7), thereby forming a europium-doped GaN single crystal thin film on the substrate (8); the temperature of the gallium metal evaporation pool (6) is 850-900°C, and the temperature of the rare earth europium metal evaporation pool (7) is 600-1000°C; Step 3: Place the europium-doped GaN single crystal film obtained in step 2 into a furnace for annealing. The annealing conditions are: nitrogen or ammonia, annealing temperature of 1000-1200°C, and annealing time of 0.5-4 h.

2. The method for preparing rare earth-doped GaN nanofilm according to claim 1, wherein: The rare earth europium metal evaporation pool (7) is arranged above the gallium metal evaporation pool (6).

3. The method for preparing rare earth-doped GaN nanofilm according to claim 1, wherein: The growth rate of the europium-doped GaN single crystal thin film on the substrate (8) is controlled at 60-120 μm / h.

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