Solar battery be made in laboratory almost has the best conversion efficiency. Unfortunately, the manufacturing process is too complicated and bringing high price, resulting in it can not do mass production. According to the literature, all kinds of solar cells’ best efficiency are：

1.Single crystal silicon：24.7%
2.Polycrystal：19.8％
3.Amorphus Silicon：14.5％
4.GaAs：25.7%
5.CIGS：18.8%
6.InGaP/GaAs//InGaAs, multijunction tandem cell：33.3％
Because the restriction of material characteristic, the yields of the solar cells’ efficiency almost has the best level. It is not easy to promote it. Multi-junction tandem solar cell has the most growth potential. According to the United States Department of Energy’s researchers’ prediction, multi-junction tandem solar cells’ efficiency can reach to 40% in 2005.

Solar cell manufacturing

To introduce solar cell’s manufacturing technology, we start to talk from the easiest procedure：single crystal silicon solar cell’s manufacturing technology.

1.Pulling：

The main raw material is Silica. Making seed to become single crystal silicon block in the crystal pulling furnaces.

2.Trimming：

Wafer which usually used in microelectronic industry, by cutting single crystal silicon block to get. But to solar cell, it has to connect wafers in a square array. To make it be more closing, it usually trim single crystal silicon block into a square at first.

3.Slicing：

Using the slicer to slice single crystal silicon block into wafer with thickness about 0.5mm.

4. Etching & Polishing：

Etching’s purpose is to remove the stress layer which be made in slicing process. Polishing’s purpose is to reduce the probability of particle’s adhesion on the cell.

5.washing：

Using DI water to remove impurity and pollutant which on the cell’s surface.

6.diffusing：

Solar cell usually use P-type substrate, by high-temperature diffusion treatment, to form a thin layer N-type semiconductor on the P-type substrate.

7.Screen Printing or deposition：

By silver adhesives printing or deposition to contact conductive electrode on the cell’s surface, then we can get a simple solar cell.