Dislocation is a common extended defect in crystalline silicon solar cells, which affects the recombination characteristics of solar cells by forming deep-level defect states in the silicon bandgap, thereby reducing the lifetime of minority carrier.
Solar cells made from multi-crystalline silicon will have efficiencies up to ~22%, while 25% single junction monocrystalline silicon solar cells have been made from electronic grade silicon. Above 1414 °C, silicon is liquid. While crystalline silicon is semiconducting, liquid silicon is metallic and very reactive with air.
Part of the book series: Springer Series in Optical Sciences ( (SSOS,volume 212)) Most solar cells are fabricated from crystalline or semicrystalline silicon since they are relatively inexpensive starting materials and the resulting solar cells are very efficient.
However, many high-efficiency silicon solar cells have a very rough surface that has been textured using a preferential etch. On single crystal silicon solar cells, this texturing results in the formation of pyramidal structures that are randomly positioned, but of the same orientation.
The cost distribution of a crystalline silicon PV module is clearly dominated by material costs, especially by the costs of the silicon wafer. Therefore, besides improved production technology, the efficiency of the cells and modules is the main leverage to bring down the costs even more.
Therefore, the optical properties of silicon are isotropic. At room temperature, photons greater than ~1.05 eV are absorbed; according to the Shockley-Queisser limit the maximum possible efficiency of a single-junction silicon solar cell is ~31.5%.