Electricity produced from solar energy is alternative to finite sources of energy such as coal and oil. Solar power installation at home or small offices has been increasing in the past decades. Micro scale solar power generation is effective to reduce fossil fuel dependence, minimize environmental pollution and meet increasing energy demand. Household energy production has advantages of reducing energy losses during the transmission from central power station (Kaku, 2011).
Silicon is used as a semiconductor material in the solar cells. Silicon is the second most abundant element on earth and its efficiency can reach up to 30 percentages in ideal conditions. Traditional silicon cells can be replaced by low cost all-carbon solar cells (Shwartz, 2012) but there is less information about its commercial uses.
Solar energy in the form of light is converted into electrical energy by using photovoltaic (PV) materials. Two types of semiconductors are used in the photovoltaic cell. Negative layer or n-type semiconductor where phosphorous is used and positive layer or p-type semiconductor where boron is used to create p-n junction with a diffusion of electrons (EC, 2009). Photons absorbed by semiconductor materials energise electrons to converge electric field at the p-n junction moving freely through the silicon atoms and producing energy as electricity (NSI, 2010).
Solar cells can be mono crystalline, polycrystalline and amorphous thin film. Mono crystalline panels are silicon wafer cut from a single silicon crystal but polycrystalline panels are cut from melted and recrystallized multifaceted crystals (NSI, 2010; WordPress, 2010). Mono crystalline panels are more efficient but expensive than polycrystalline panels. Silicon atoms in a thin layer made thin film or amorphous solar cells which have low production cost (WordPress, 2010).
Kaku, M. (2011) Physics of the Future. First Edition. Penguin Books. USA. pp. 210-255.
Noble Solar Industries (NSI) (2010) How Solar Energy Works. [Online] Available at http://www.noblesolarindustries.com/howsolarenergyworks.html [Accessed on 25 March 2013].
Schwartz, M (2012) Stanford Scientists Build the First All-carbon Solar Cell. [Online] Available at http://news.stanford.edu/news/2012/october/carbon-solar-cell-103112.html [Accessed on 1 February 2013].
WordPress.com (2010) Solar technology explained – the differences between crystalline and thin film, mono and poly etc. [Online] Available at wbbcc.files.wordpress.com/2010/08/solar-technology-explained.pdf [Accessed on 25 March 2013].