CN105428430A - Multi-junction GaAs solar cell surface grid line structure - Google Patents

Abstract

The invention discloses a grid line structure on the surface of a multi-junction GaAs solar cell, including a solar cell, the effective light-receiving area on the surface of the solar cell is circular, and the part outside the effective light-receiving area on the solar cell is the main grid line In the effective light-receiving area, a number of fine grid lines are arranged radially and evenly distributed around the center of the solar cell. After being collected, it is transmitted to the busbar. The present invention adopts a circular light-receiving area design. For the case where the spot shape of the optical system such as some spherical or aspherical curved surface optical systems converges is approximately circular, the effective utilization rate of the solar cell has been improved. At the same time, due to the radial The design of the grid lines makes the density of the thin grid lines closer to the center of the light-receiving area greater, which increases the collection and current-carrying capacity of the high current density generated by the central high-light-intensity area, and improves the efficiency of the solar cell.

Description

A gridline structure on the surface of a multi-junction GaAs solar cell

technical field

The invention belongs to the technical field of solar energy utilization, and in particular relates to a grid line structure on the surface of a multi-junction GaAs solar cell.

Background technique

Solar energy has excellent characteristics such as cleanness, no geographical limitation of resources, and inexhaustibility for human beings. It is more and more popular among people. Among them, the technology of solar photovoltaic utilization, that is, the direct conversion of sunlight into electrical energy through photovoltaic devices, is particularly eye-catching.

In traditional photovoltaic solar cell modules, the use of solar cells is relatively large, resulting in the cost of photovoltaic power generation being several times higher than conventional power generation costs, thus limiting the large-scale application of photovoltaic power generation technology and restricting the development of the entire industry. In order to save the usage of solar cells and reduce the production cost of photovoltaic solar cell components, light concentrating technology is often used in existing photovoltaic solar cell components, so that the light is concentrated and then irradiated on high-efficiency multi-junction solar cells to Reduce the amount of solar cells used.

As shown in Figure 1, the light-receiving area of the multi-junction solar cell currently on the market is generally rectangular, and its main grid lines 3 are distributed on both sides, and there are many thin grid lines 4 for collecting photo-generated current in the middle of the cell, and the thin The grid lines are evenly arranged, and are combined with other solar cells in series and parallel through the main grid lines to obtain the required voltage and current. This design is more reasonable for the square uniform light spot formed after passing through the light-condensing system, but the shape of the light spot 6 actually converged by some other optical systems such as some spherical or aspherical curved surface optical systems is approximately circular, and the energy distribution of the light spot is not the same. Unevenness, generally showing a trend of strong center and weak edge, so the design of this rectangular light-receiving area cannot effectively collect photo-generated current. The loss of cell efficiency, as shown in Figure 2, when the near-circular light spot after the concentrating system is irradiated on the surface of the solar cell, it can be seen that in this case, the utilization rate of the light-receiving area on the surface of the solar cell is not high, and the light-receiving area The light intensity in the central area is extremely high, while the edge is weaker, and the thin grid lines in this design are evenly distributed, so the current density carried by the thin grid lines at the center light intensity is relatively large, resulting in efficiency loss. At the same time, the cost of multi-junction solar cells produced by the MOCVD process is very high, and the low utilization rate of the light-receiving area leads to an increase in cost.

Contents of the invention

The purpose of the present invention is to provide a multi-junction GaAs solar cell surface grid structure capable of improving the effective utilization rate of the solar cell and the current collection and carrying capacity in view of the above existing problems.

The technical scheme of the present invention is achieved in the following way: a multi-junction GaAs solar cell surface grid line structure, including a solar cell, is characterized in that: the effective light-receiving area on the surface of the solar cell is circular, and on the solar cell, the effective The part outside the light-receiving area is the main grid line. In the effective light-receiving area, a number of fine grid lines are arranged radially and uniformly distributed around the center of the solar cell, and the light energy injected into the effective light-receiving area is effectively converted into Electric energy and photoelectric conversion current are collected through the thin grid lines and then transmitted to the main grid lines.

According to the multi-junction GaAs solar cell surface grid line structure of the present invention, a central ring thin grid line is arranged at the center of the solar cell, and the corresponding solar cell in the central ring thin grid line is not provided with Thin grid lines, several thin grid lines in a radial shape are all connected with the central circular ring thin grid lines.

The present invention adopts a circular light-receiving area design. For the case where the spot shape of the optical system such as some spherical or aspherical curved surface optical systems converges is approximately circular, the effective utilization rate of the solar cell has been improved. At the same time, due to the radial The design of the grid lines makes the density of the thin grid lines closer to the center of the light-receiving area greater, which increases the collection and current-carrying capacity of the high current density generated by the central high-light-intensity area, and improves the efficiency of the solar cell.

Description of drawings

FIG. 1 is a schematic diagram of the structure of grid lines on the surface of an existing multi-junction solar cell.

Fig. 2 is a schematic diagram of a circular concentrated light spot irradiating an existing multi-junction solar cell.

Fig. 3 is a structural schematic diagram of the present invention.

Fig. 4 is a schematic diagram of a circular concentrated light spot irradiating on the solar cell of the present invention.

Marks in the figure: 1 is the solar cell, 2 is the effective light-receiving area, 3 is the main grid line, 4 is the thin grid line, 5 is the central ring thin grid line, and 6 is the light spot.

detailed description

Below in conjunction with accompanying drawing, the present invention is described in detail.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Figures 3 and 4, a grid line structure on the surface of a multi-junction GaAs solar cell includes a solar cell 1, and the effective light-receiving area 2 on the surface of the solar cell 1 is circular, for optical systems such as some spherical or aspherical curved surfaces When the shape of the light spot 6 converged by the optical system is approximately circular, the effective utilization rate of the solar cell can be improved; The effective light-receiving area 2 is provided with a number of thin grid lines 4 that are evenly distributed radially around the center of the solar cell 1. The light energy incident on the effective light-receiving area 2 is effectively converted into electrical energy, and the photoelectrically converted current passes through the thin grid lines. 4 After collecting, it is transmitted to the main grid line 3. Due to the arrangement of the radial thin grid lines, the closer to the center of the light-receiving area, the greater the density of the thin grid lines, and the energy distribution of the spot shows a tendency that the center is strong and the edge is weak. , which increases the collection and carrying capacity of the high current density generated by the thin grid lines on the surface of the solar cell to the high light intensity area in the center, thereby improving the efficiency of the solar cell.

Wherein, at the central position of the solar cell 1, a central ring thin grid line 5 is arranged, and the corresponding solar cell 1 in the central ring ring thin grid line 5 is not provided with a thin grid line, and several thin grid lines in a radial shape The wires 4 are all connected with the thin grid wires 5 of the central ring. Because the light intensity in the center of the converged light spot is extremely high, and the thin grid lines form a cross junction in the central area, because the thin grid lines reflect the concentrated light incident on the surface of the solar cell, and the light intensity in the center is extremely high, so It will cause the cross joint point of the fine grid lines in the center of the light-receiving area to have a more obvious reflection effect on high-intensity incident light. By designing the central area of the solar cell as a blank area, that is, there is no thin grid line in the central ring thin grid line, it is beneficial to reduce the reflection effect of the thin grid line on incident light, and because the central ring thin grid line surrounds, It can also ensure the collection of the photo-generated current generated in the central area, so that the efficiency of the solar cell can be further improved.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (2)

1. tie GaAs solar battery surface grid line structure one kind more, comprise solar cell (1), it is characterized in that: effective light area (2) on described solar cell (1) surface is rounded, on described solar cell (1), part outside effective light area (2) is main gate line (3), radially equally distributed some thin grid lines (4) are provided with centered by solar cell (1) mid point in described effective light area (2), the luminous energy being injected into effective light area (2) is effectively doubly converted to electric energy, the electric current of opto-electronic conversion is reached in main gate line (3) after being collected by thin grid line (4).

2. many knot GaAs solar battery surface grid line structures according to claim 1, it is characterized in that: the center of described solar cell (1) is provided with the thin grid line of central circular (5), solar cell (1) corresponding in the thin grid line of described central circular (5) is not provided with thin grid line, and all thin with the central circular grid line (5) of radial some thin grid lines (4) is connected.