During the past few decades, crystalline silicon solar cells are mainly applied on the utilization of solar energy in large scale, which are mainly classified into three types, i.e., mono-crystalline silicon, multi-crystalline silicon and thin film, respectively .
Single crystalline silicon is usually grown as a large cylindrical ingot producing circular or semi-square solar cells. The semi-square cell started out circular but has had the edges cut off so that a number of cells can be more efficiently packed into a rectangular module.
Multi and single crystalline are largely utilized in manufacturing systems within the solar cell industry. Both crystalline silicon wafers are considered to be dominating substrate materials for solar cell fabrication.
The device structure of a silicon solar cell is based on the concept of a p-n junction, for which dopant atoms such as phosphorus and boron are introduced into intrinsic silicon for preparing n- or p-type silicon, respectively. A simplified schematic cross-section of a commercial mono-crystalline silicon solar cell is shown in Fig. 2.
This technique provides a promising approach for low-cost silicon solar cells production and potentially for high quality crystalline silicon film production for other applications. Silicon dioxide is the primary source for silicon production.
The first generation of the solar cells, also called the crystalline silicon generation, reported by the International Renewable Energy Agency or IRENA has reached market maturity years ago . It consists of single-crystalline, also called mono, as well as multicrystalline, also called poly, silicon solar cells.