Silicon is the most widely used material for solar cells due to its abundance in nature, stability, non-toxicity and well established refining and processing technologies. This chapter, which is divided into five sections, presents a brief review on the research progress of silicon as photovoltaic materials.
Silicon solar cells are the most broadly utilized of all solar cell due to their high photo-conversion efficiency even as single junction photovoltaic devices. Besides, the high relative abundance of silicon drives their preference in the PV landscape.
PV Solar Industry and Trends Approximately 95% of the total market share of solar cells comes from crystalline silicon materials . The reasons for silicon’s popularity within the PV market are that silicon is available and abundant, and thus relatively cheap.
The first step in producing silicon suitable for solar cells is the conversion of high-purity silica sand to silicon via the reaction SiO 2 + 2 C → Si + 2 CO, which takes place in a furnace at temperatures above 1900°C, the carbon being supplied usually in the form of coke and the mixture kept rich in SiO 2 to help suppress formation of SiC.
As one of the PV technologies with a long standing development history, the record efficiency of silicon solar cells at lab scale already exceeded 24% from about 20 years ago (Zhao et al., 1998).
A solar cell in its most fundamental form consists of a semiconductor light absorber with a specific energy band gap plus electron- and hole-selective contacts for charge carrier separation and extraction. Silicon solar cells have the advantage of using a photoactive absorber material that is abundant, stable, nontoxic, and well understood.