A packaging structure for improving the quantum efficiency of SiC photoconductive devices

Abstract

The present invention discloses a packaging structure for improving the quantum efficiency of SiC photoconductive devices, comprising a photoconductive device and a copper column; the front and back sides of the photoconductive device are bonded to the copper column, and the positions of the two copper columns correspond; a lens group is also arranged above the front of the photoconductive device; the lens group is limited in the copper column above the front of the photoconductive device; the lens group comprises a vortex phase plate and a convex lens; the vortex phase plate and the convex lens are arranged in parallel, and the vortex phase plate is arranged directly above the convex lens. The present invention introduces a combination of a vortex phase plate and a convex lens into the packaging structure of the SiC photoconductive device to achieve obliquely incident annular light, solves the problem of low quantum efficiency and light absorption rate in the non-coplanar photoconductive device; improves the effective absorption ratio of the photoconductive device to the incident light, and enhances the response ability of the photoconductive device to external light excitation.

Description

Technical Field

[0001] The present invention relates to the technical field of photoconductive devices, and in particular to a packaging structure for improving the quantum efficiency of SiC photoconductive devices. Background Art

[0002] The application of photoconductive devices in high-power fields and ultrafast electronic technology has aroused great interest, and the future prospects are promising. Silicon carbide (SiC) has become a very promising photoconductive device material due to its advantages such as high critical electric field, high electron saturation velocity, high thermal conductivity and thermal stability. However, the biggest difficulty hindering the practical application of SiC photoconductive devices is its extremely low quantum efficiency, which requires a large laser power to excite the photoconductive device to generate enough carriers and sufficient output. High-power lasers require additional volume and larger supporting power facilities, making the application system of photoconductive devices too complicated and expensive.

[0003] The quantum efficiency of photoconductive devices is mainly divided into two parts: light absorption rate and light excitation rate. The light absorption rate determines the device's effective absorption capacity of external laser energy, while the light excitation rate determines the absorbed light energy's effective activation capacity of the device's internal carriers.

[0004] Therefore, effectively improving the quantum efficiency of photoconductive devices through appropriate processes or packaging structures can significantly reduce the demand for corresponding light sources and supporting systems, which is conducive to promoting the practical application of photoconductive devices. Summary of the invention

[0005] The purpose of the present invention is to provide a packaging structure for improving the quantum efficiency of SiC photoconductive devices, so as to solve the problems existing in the above-mentioned prior art, and to improve the effective absorption ratio of the photoconductive device to the incident light, and enhance the response ability of the photoconductive device to the external light excitation.

[0006] To achieve the above object, the present invention provides the following solution: The present invention provides a packaging structure for improving the quantum efficiency of a SiC photoconductive device, comprising a photoconductive device and a copper column; both the front and back sides of the photoconductive device are bonded to the copper column, and the positions of the two copper columns correspond to each other; a lens group is also arranged above the front side of the photoconductive device; the lens group is confined in the copper column above the front side of the photoconductive device;

[0007] The lens group includes a vortex phase plate and a convex lens; the vortex phase plate and the convex lens are arranged in parallel, and the vortex phase plate is arranged directly above the convex lens.

[0008] Preferably, by designing the packaging structure and the optical path, the way in which the incident light enters the optical waveguide device is changed, the optical path of the incident light inside the optical waveguide device is enhanced, and the light absorption rate of the optical waveguide device is effectively improved.

[0009] Preferably, the vortex phase plate causes the axis in the propagation direction of the parallel light wave front to spiral forward. This rotation causes the light beams to cancel each other out at the optical axis, projecting onto a plane and looking like a halo with a dark hole in the center, which is a special light field with a spiral phase structure and orbital angular momentum.

[0010] The photoconductive device comprises a photoconductive plate, a reflective electrode, a contact electrode and an anti-reflection and anti-reflection film; the contact electrodes are arranged on both the front and back sides of the photoconductive plate; the contact electrode is a circular ring structure, and the two copper pillars are respectively bonded and fixed to the two contact electrodes; the anti-reflection and anti-reflection film is deposited on the front side of the photoconductive plate; the reflective electrode is evaporated on the back side of the photoconductive plate; the reflective electrode and the anti-reflection and anti-reflection film are both confined within the contact electrode.

[0011] The bonding medium between the copper column and the contact electrode is silver paste, which is cured by high-temperature baking; the copper column is 6cm-10cm high, with a circular cross-section, an inner diameter of 5mm-7mm, an outer diameter of 6mm-8mm, and a difference of 1mm between the inner and outer diameters.

[0012] The high temperature baking is performed at a temperature of 140° C. to 170° C. and for a time of 3 hours to 3.5 hours.

[0013] The light guide plate is 4H-SiC, and the 4H-SiC material is doped with vanadium; the effective doping concentration of the vanadium is 10^ 16 cm -3 -10^ 17 cm -3 The thickness of the light guide plate is 800-1500 μm, and the size of the light guide plate is 12 mm×12 mm.

[0014] The reflective electrode is a metal electrode, the metal of which is Ag, with a thickness of 100nm-200nm and a diameter of 5mm-7mm.

[0015] The contact electrode is made of Ni / Au, has a thickness of 100nm-300nm, an inner diameter of 5mm-7mm, an outer diameter of 6mm-8mm, and a difference of 1mm between the inner and outer diameters.

[0016] The anti-reflection and anti-reflection film has a thickness of 300nm-700nm, is circular, and has a diameter of 5mm-7mm.

[0017] The vortex phase plate is 3cm-5cm away from the surface of the anti-reflection and anti-reflection film, is circular, and has a diameter of 5mm-7mm; the convex lens is 1cm-2cm away from the surface of the anti-reflection and anti-reflection film, and has a diameter of 5mm-7mm.

[0018] The present invention discloses the following technical effects: the present invention realizes obliquely incident annular light by introducing a combination of a vortex phase plate and a convex lens into the packaging structure of a SiC photoconductive device, thereby solving the problems of low quantum efficiency and light absorption rate in anisotropic photoconductive devices; improving the effective absorption ratio of the photoconductive device to incident light, and enhancing the response capability of the photoconductive device to external light excitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 is a top view of the light guide device in the present invention;

[0022] Figure 3 This is a cross-sectional light intensity distribution diagram after passing through the vortex phase plate in the present invention.

[0023] Among them, 1-light guide plate, 2-reflection electrode, 3-contact electrode, 4-anti-reflection and anti-reflection film, 5-vortex phase plate, 6-convex lens, 7-copper column. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The present invention provides a packaging structure for improving the quantum efficiency of a SiC photoconductive device, comprising a photoconductive device and a copper pillar 7; the front and back sides of the photoconductive device are bonded to the copper pillar 7, and the positions of the two copper pillars 7 correspond to each other; a lens group is also arranged above the front side of the photoconductive device; the lens group is confined in the copper pillar 7 above the front side of the photoconductive device;

[0027] The lens group includes a vortex phase plate 5 and a convex lens 6 ; the vortex phase plate 5 and the convex lens 6 are arranged in parallel, and the vortex phase plate 5 is arranged directly above the convex lens 6 .

[0028] The photoconductive device comprises a photoconductive plate 1, a reflective electrode 2, a contact electrode 3 and an anti-reflection and anti-reflection film 4; the contact electrodes 3 are arranged on both the front and back sides of the photoconductive plate 1; the contact electrode 3 is a circular ring structure, and two copper pillars 7 are respectively bonded and fixed to the two contact electrodes 3; the anti-reflection and anti-reflection film 4 is deposited on the front side of the photoconductive plate 1; the reflective electrode 2 is evaporated on the back side of the photoconductive plate 1; the reflective electrode 2 and the anti-reflection and anti-reflection film 4 are both confined within the contact electrode 3.

[0029] The bonding medium between the copper column 7 and the contact electrode 3 is silver paste, which is cured by high-temperature baking. The copper column 7 is 6cm-10cm high, with a circular cross section, an inner diameter of 5mm-7mm, an outer diameter of 6mm-8mm, and a difference of 1mm between the inner and outer diameters.

[0030] The high temperature baking temperature is 140 ℃ -170 ℃, and the time is 3 hours -3.5 hours.

[0031] The light guide plate 1 is 4H-SiC, and the 4H-SiC material is doped with vanadium; the effective doping concentration of vanadium is 10^ 16 cm -3 -10^ 17 cm -3 The thickness of the light guide plate 1 is 800-1500 μm, and the size of the light guide plate 1 is 12 mm×12 mm.

[0032] The reflective electrode 2 is a metal electrode, and the metal thereof is Ag. The reflective electrode 4 has a thickness of 100 nm-200 nm and a diameter of 5 mm-7 mm.

[0033] The metal composition of the contact electrode 3 is Ni / Au, the thickness is 100nm-300nm, the inner diameter is 5mm-7mm, the outer diameter is 6mm-8mm, and the difference between the inner and outer diameters is 1mm.

[0034] The anti-reflection and anti-reflection film 4 has a thickness of 300nm-700nm, is circular, and has a diameter of 5mm-7mm.

[0035] The vortex phase plate 5 is 3cm-5cm away from the surface of the anti-reflection and anti-reflection film 4, is circular, and has a diameter of 5mm-7mm; the convex lens 6 is 1cm-2cm away from the surface of the anti-reflection and anti-reflection film 4, and has a diameter of 5mm-7mm.

[0036] The specific implementation process of the present invention is as follows: the vortex phase plate 5 can correct the incident parallel light into annular light, which is diverged through the convex lens 6 and incident into the light guide plate 1 .

[0037] In one embodiment of the present invention, the specific steps for fixing the copper pillar 7 to the photoconductive device are as follows: silver paste is applied to the surfaces of the positive and negative contact electrodes 3 of the photoconductive device, the copper pillar 7 and the contact electrode 3 are adhered and squeezed to fix, and then placed in an oven and baked at above 150°C for 3 hours, and then taken out and allowed to cool naturally.

[0038] In one embodiment of the present invention, the anti-reflection and anti-reflection film material is aluminum- and gallium-doped zinc oxide material (AZO, GZO), which is deposited at the center of the front surface of the photoconductive device by magnetron sputtering or other methods.

[0039] In one embodiment of the present invention, Figure 3 The parallel light passes through the vortex phase plate 5 and forms a cross-sectional light intensity diagram of the circular light before reaching the convex lens 6, which changes the relative intensity of the light in the same cross section, so that the relative light intensity of the original light in the same cross section is converted into Figure 3 The cross-sectional relative intensity.

[0040] The present invention discloses the following technical effects: the present invention realizes obliquely incident annular light by introducing a combination of a vortex phase plate and a convex lens into the packaging structure of a SiC optical waveguide device, which is beneficial to improving the effective absorption ratio of the optical waveguide device to the incident light and enhancing the response capability of the optical waveguide device to external light excitation.

[0041] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0042] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A packaging structure for improving the quantum efficiency of a SiC photoconductive device, characterized in that: include: A photoconductive device and a copper column (7); the front and back sides of the photoconductive device are bonded to the copper column (7), and the positions of the two copper columns (7) correspond to each other; a lens group is also arranged above the front side of the photoconductive device; the lens group is confined within the copper column (7) above the front side of the photoconductive device; The lens group comprises a vortex phase plate (5) and a convex lens (6); the vortex phase plate (5) and the convex lens (6) are arranged in parallel, and the vortex phase plate (5) is arranged directly above the convex lens (6); The photoconductive device comprises a photoconductive plate (1), a reflective electrode (2), a contact electrode (3) and an anti-reflection and anti-reflection film (4); the contact electrode (3) is arranged on both the front and back sides of the photoconductive plate (1); the contact electrode (3) is a circular ring structure, and the two copper pillars (7) are respectively bonded and fixed to the two contact electrodes (3); the anti-reflection and anti-reflection film (4) is deposited on the front side of the photoconductive plate (1); the reflective electrode (2) is evaporated on the back side of the photoconductive plate (1); the reflective electrode (2) and the anti-reflection and anti-reflection film (4) are both confined within the contact electrode (3); The material of the anti-reflection and anti-reflection film (4) is a zinc oxide material doped with aluminum and gallium.

2. A packaging structure for improving the quantum efficiency of SiC photoconductive devices according to claim 1, characterized in that: The bonding medium between the copper column (7) and the contact electrode (3) is silver paste, which is cured by high-temperature baking; the copper column (7) has a height of 6 cm-10 cm, a circular cross-section, an inner diameter of 5 mm-7 mm, an outer diameter of 6 mm-8 mm, and a difference of 1 mm between the inner and outer diameters.

3. A packaging structure for improving the quantum efficiency of SiC photoconductive devices according to claim 2, characterized in that: The high temperature baking is performed at a temperature of 140° C. to 170° C. and for a time of 3 hours to 3.5 hours.

4. The packaging structure for improving the quantum efficiency of SiC photoconductive devices according to claim 1, characterized in that: The light guide plate (1) is 4H-SiC, and the 4H-SiC material is doped with vanadium; the effective doping concentration of the vanadium is 10^ 16 cm -3 -10^ 17 cm -3 The thickness of the light guide plate (1) is 800-1500 μm, and the size of the light guide plate (1) is 12 mm×12 mm.

5. The packaging structure for improving the quantum efficiency of SiC photoconductive devices according to claim 1, characterized in that: The reflective electrode (2) is a metal electrode, the metal of which is Ag; the reflective electrode (4) has a thickness of 100 nm to 200 nm and a diameter of 5 mm to 7 mm.

6. The packaging structure for improving the quantum efficiency of SiC photoconductive devices according to claim 1, characterized in that: The contact electrode (3) is made of Ni / Au, has a thickness of 100nm-300nm, an inner diameter of 5mm-7mm, an outer diameter of 6mm-8mm, and a difference of 1mm between the inner and outer diameters.

7. The packaging structure for improving the quantum efficiency of SiC photoconductive devices according to claim 1, characterized in that: The anti-reflection and anti-reflection film (4) has a thickness of 300nm-700nm, is circular, and has a diameter of 5mm-7mm.

8. The packaging structure for improving the quantum efficiency of SiC photoconductive devices according to claim 1, characterized in that: The vortex phase plate (5) is 3 cm to 5 cm away from the surface of the anti-reflection and anti-reflection film (4), is circular in shape, and has a diameter of 5 mm to 7 mm; the convex lens (6) is 1 cm to 2 cm away from the surface of the anti-reflection and anti-reflection film (4), and has a diameter of 5 mm to 7 mm.

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