Compare the advantages and disadvantages of common photovoltaic cells.

I will introduce the common types of photovoltaic cells and their advantages and disadvantages in detail. First, monocrystalline silicon solar cells

The structure of monocrystalline silicon solar cell mainly includes front comb electrode, antireflection film, N-type layer, PN junction, P-type layer and back electrode. Monocrystalline silicon solar cells are widely used in space and on the ground. This kind of solar cell takes high-purity monocrystalline silicon rods as raw materials. Monocrystalline silicon rods are sliced and PN junctions are formed through a series of semiconductor processes. Then, the grid line is made by screen printing, and the back electrode is made by sintering process, so as to make the monocrystalline silicon solar cell monolithic. Monomers can be assembled into solar cell modules (solar panels) in series and parallel according to the required specifications, forming a certain output voltage and current. Finally, the solar cell modules are encapsulated by a frame to form solar cell arrays with different sizes. At present, the photoelectric conversion efficiency of monocrystalline silicon solar cells is about 15%, and the laboratory results are above 20%.

Second, polysilicon solar cells.

Polycrystalline silicon thin film solar cell grows polycrystalline silicon thin film on low-cost substrate material, and uses relatively thin crystalline silicon layer as the active layer of solar cell, which not only maintains the high performance and stability of crystalline silicon solar cell, but also greatly reduces the material consumption and battery cost. The working principle of polycrystalline silicon thin film solar cells, like other solar cells, is based on the interaction between sunlight and semiconductor materials to form photovoltaic effect. Most polysilicon materials used in solar cells are aggregates containing a large number of single crystal particles, or are melted with waste sub-single crystal silicon and metallurgical grade silicon materials, and then injected into graphite molds to obtain polysilicon ingots. This silicon ingot is cast into a cube, so that it can be sliced and processed into a square battery. The manufacturing process of polycrystalline silicon solar panels is similar to that of monocrystalline silicon solar panels, and its photoelectric conversion efficiency is about 12%, which is slightly lower than that of monocrystalline silicon solar panels. However, the material manufacturing is simple, power consumption is saved and the total production cost is low, so it has been greatly developed.

3. Amorphous silicon solar cells

Amorphous silicon solar cells are composed of transparent oxide film (TCO), amorphous silicon thin film P-I-N layer (I layer is intrinsic absorption layer) and back electrode metal film layer. The substrate can be aluminum alloy, stainless steel, special plastic, etc. It is completely different from the manufacturing method of monocrystalline silicon and polycrystalline silicon solar cells, with less silicon consumption and lower power consumption. There are many manufacturing methods, and the most common one is to obtain N-type or P-type amorphous silicon films by glow discharge. The base material is usually glass or stainless steel plate. Amorphous silicon solar cells are very thin, which can be made into laminated cells or integrated circuits, and can also be made into multiple series cells at a time to obtain higher voltage. At present, the photoelectric conversion efficiency of amorphous silicon solar cells is low, and the international advanced level is about 10%.

4. Multicomponent solar cells

Polycrystalline thin film solar cells of cadmium sulfide and cadmium telluride have higher efficiency than amorphous silicon thin film solar cells and lower cost than monocrystalline silicon solar cells. On the basis of extensive and in-depth application research, cadmium telluride thin film solar cells in many countries in the world have moved from laboratory research stage to large-scale industrial production.

1. cadmium sulfide solar cell: Although the photoelectric efficiency has been improved to 9%, it still cannot compete with polysilicon solar cells. Compared with amorphous silicon thin film battery, the manufacturing process is simpler.

2. Gallium arsenide solar cell: Gallium arsenide is suitable to match the solar spectrum and is resistant to high temperature. At 250℃, the photoelectric conversion performance is still very good, and its maximum photoelectric conversion efficiency is about 30%, which is especially suitable for high-temperature concentrating solar cells. Due to the lack of gallium, arsenic is toxic and the manufacturing cost is high, which affects the development of this solar cell.

3. Copper indium selenium solar cell: a solar cell made of ternary compound semiconductors of copper, indium and selenium. It is a polycrystalline thin film structure with low material consumption, low cost and stable performance, and the photoelectric conversion efficiency is above 10%. Therefore, it is a new type of solar cell that can compete with amorphous silicon thin film solar cells.

Verb (abbreviation of verb) Nanocrystalline chemical solar cell

Dye-sensitized nanocrystalline solar cells mainly include a glass substrate coated with a transparent conductive film, a dye-sensitized semiconductor material, a counter electrode and an electrolyte. Its anode is dye-sensitized semiconductor film (TiO2 film) and its cathode is platinum-plated conductive glass. Nanocrystalline TiO2 _ 2 solar cells have the advantages of low cost, simple process and stable performance. Its photoelectric efficiency is stable above 10%, its manufacturing cost is only1/5 ~1/and its service life can reach more than 20 years.

6. Laminated solar cells

The stacked battery can stack the performance of the battery. The thin layer of solar cells can make it thinner, so the stacking of devices becomes more realistic and feasible. Stacked batteries can be the same kind of stacked devices or different kinds of stacked devices. Because of the different light response performance of the photosensitive part, each laminated unit can absorb and utilize sunlight in different bands. After lamination, all bands of sunlight can be well absorbed; At the same time, due to the coupling effect between devices, the overall light energy conversion efficiency can reach a higher level.

Seven. Flexible solar cell

The flexible solar panel is made of high crystalline silicon material, and is pressed with high-strength and light-transmitting special tempered glass for solar energy and a special sealing material layer with high performance and ultraviolet radiation resistance. It has many advantages such as snow and ice resistance, earthquake resistance, compression resistance, etc., and can be used normally even under the harsh conditions of drastic temperature changes. Therefore, flexible batteries can be used in many fields where flat solar cells are not competent, such as solar cars, airplanes, airships, buildings, textiles, tents, clothing, helmets, toys and other special curved surfaces.