4.1 Generations of solar cells
In the previous article, we realized that crystalline silicon solar cells were more realistic and cost-effective in commercial solar electricity generation compared to GaAs solar cells although crystalline silicon solar cells were less efficient than GaAs solar cells. In this article, we are going to discuss the biography of crystalline silicon solar cell technology and the latest trends in crystalline silicon cell industry.
Depending on the degree of crystallinity, we have a variety of silicon allotropes namely, single-crystalline silicon (s-Si), polycrystalline silicon (pc-Si), nanocrystalline silicon and amorphous silicon. While amorphous silicon and nanocrystalline silicon are used in thin film solar cell technologies (2nd generation solar cells), both pc-Si and s-Si are used to fabricate 1st generation crystalline silicon solar cells.
Genesis of crystalline silicon solar cells
The first c-Si solar cell was developed by Bell laboratories in 1953 with an efficiency of 4.5 % and they improved the efficiency to 6% in 1954 [1, 2]. It was an impressive efficiency and amazing beginning at the time and astounded the scientific community all around the world attracting much attention from researchers leading to incredible advances in terms of $/W (system cost), $/kWh (cost of electricity), efficiency, and system durability.
Soon after the mind-blowing invention of efficient c-Si solar cells, researchers started to think of its potential applications and finally, they outmatched.
What did they focus on?
No…. They did not think of developing solar cells to pump water, to light up cities, or to keep the refrigerators cool but to power space satellites outside the Earth.
Nobody tried to install solar PVs on a house or factory.
Nobody invested in a solar PV park.
….as solar PV were too much expensive.
Anyway, growing interest urged to develop solar PVs for terrestrial applications. Sharp Solar was one of the frontrunners in research and development. It was founded as a subsidy of Sharp Electronics in 1959. Braking the ice, they started manufacturing commercial solar modules in 1964. Although it was not initially economical to illuminate a single village at night, the company could install solar panels on as many as 256 lighthouses by 1972.  And it showcased the potential of solar PV technology to be an alternative to black gold!
Oil embargo happened in 1973 was also a salutary blessing in the development of solar PV technology. As other companies like Sharp Solar and Phillips came into play, the price of solar modules started to drop dramatically.
Solar PVs are no longer big-tickets. They are now much affordable, as never before, even for average electricity customers who wish to make their energy bill zero or negative. Crystalline silicon solar cells are the most efficient solar PV technology available for commercial electricity generation purposes. They have never lost their battle to retain their influence in terrestrial solar PV applications. While crystalline solar cell technology has been dominating in the market, s-Si and pc-Si technologies have also been competing each other. It could be observed that pc-Si solar cells have outmaneuvered their s-Si twin brothers in the current market. s-Si solar cells represent only 33% of the current PV market while pc-Si solar cells make up 53% of the market . Anyway, their cumulative contribution to the terrestrial solar PV market is remarkable and is about 86%. While two technologies are challenging each other, they are closely working together against climate change and the greenhouse effect. And both are now increasingly exerting an unprecedented pressure on the fossil fuel market leading to a downward trend in the fossil fuel prices.
 G. L. Pearson, 18th IEEE Photovoltaic Specialists Conference, PV founders award luncheon (1985).
 D. M. Chapin , C. S. Fuller , G. L. Pearson , J. Appl. Phys. 25 , 676 (1954).
 Green, M. A. (2005). Silicon photovoltaic modules: a brief history of the first 50 years. Progress in Photovoltaics: Research and applications, 13 (5), 447-455.
 Tao M. Inorganic Photovoltaic Solar Cells: silicon and beyond. The Electrochemical Society Interface 2008:30–5