Gail Alvares talks to Niraj Lal, a scientist on the discovery of a new material in the solar cells that comes with specific light wavelengths. The sunlight absorbed by the silicon solar cells like the infrared light coming with 1-micrometer wavelength. Remember sunlight is high in energy and it needs to be captured. Nij is currently developing materials for the efficient capture of sun’s energy especially in the visible range of approximately 400-800nm. Nij’s idea is developing a tandem cell capable of capturing short wavelength light allowing infrared beams to pass through to be captivated by the silicon cell.
Tandem solar cells are crystalline silicon presenting low-cost solar cells with projected efficiencies of over 30%. The dual junction solar cell configuration consists of the c-Si bottom cell of high efficiency and a thin film cell that is made of low-cost materials. To reach the minimum efficiency it is important to reach 30% tandem efficiency ranging from 22% to 14% with a bandgap of 1.5 eV to2 eV respectively. The material needs are defined using a simple model with four terminal tandem in terms of the electronic band gap, luminescence, optical absorption and carrier transport.
So tandem solar cells are the latest entrant in the field of solar technology for powering up homes.
Read More : What Storytelling Has In Store For The Future?