Reflective optical element and its design method and application in solar cells

Abstract

The invention provides a reflective optical element, a design method thereof and applications in solar cells. The reflective optical element is provided with a reflecting surface which can carry out color separation and focusing on incident light containing a plurality of wave lengths according to the wave length, and the reflecting surface is a convex-concave surface which concaves downward by different depths. The design method is that the designed modulation depths of a plurality of sampling points of the reflecting surface are acquired based on the depth of a reflecting grating used for carrying out color separation on the incident light containing a plurality of wave lengths and the depth of a reflective focusing lens used for carrying out focusing on the incident light after color separation. Phase modulation of the reflective optical element according to the invention is stronger than that of a transmission type structure, thereby enabling the processing difficulty of the reflective optical element to be lower. In addition, materials of the reflective optical element provided by the invention are wide in selection range and low in cost. For example, various types of metals can be adopted.

Description

technical field [0001] The invention relates to the field of optics, in particular to a reflective optical element for color separation and focusing, its design method and its application in solar cells. Background technique [0002] Solar energy is a non-polluting, inexhaustible renewable energy source. An important way to utilize solar energy is to use solar cells to convert light energy into electrical energy. The main principle of solar cells, taking semiconductors as an example, is to use the photovoltaic effect of semiconductor materials to absorb the energy of sunlight and convert it into electrical energy. The two main factors restricting the widespread utilization of solar energy are low photoelectric conversion efficiency and high cost. Currently, cost reductions are mainly achieved by focusing sunlight to reduce the use of expensive solar cell materials. In actual use, due to the different bandgap structures of different semiconductor materials, light with energ...

AI Technical Summary

Problems solved by technology

In order to obtain higher color separation efficiency, this kind of dichroic mirror usually needs to be coated with more than ten layers, or even dozens of layers, which is technically difficult

The second is to use a combination of lenses and prisms to split light, which makes the optical device bulky

The disadvantage of the existing parallel structure is that the cost of the optical system will be very high

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