Scientists of the Kavli Institute and the Chemical Engineering department of TU Delft have established that light can influence the free movement of electrons in layers of linked semiconductor nano-particles.
The new theory assumes significance in the formulation of efficient functioning and cheaper quantum dot solar cells. The finding of the research was published recently in the online scientific journal, Nature Nanotechnology.
The crystalline silicon solar panels presently available suffer high-cost of manufacturing. The cheaper solar cells such as organic solar cells currently available for use have a maximum solar conversion efficiency of 8% thus making them inefficient. The power conversion efficiency of cheaper solar cells can be increased by deploying semiconductor nano-particles known as quantum dots.
It is theoretically proved that the energy conversion efficiency of these solar cells can be augmented to 44%, which is partly ascribable to the avalanche effect established in 2008 by the scientists from the FOM Foundation and TU Delft. Unlike the current day solar cells, where a captivated light particle stimulates only one electron in a quantum dot solar cell, a received light particle stimulates number of electrons thus increasing the conversion efficiency of the solar cell.
Up till now, the generation of electron-hole pairs utilizing the lights influence was established only within the bounds of a quantum dot. For the purpose of using them in solar cells it is important that electrons and holes should remain in motion to generate power that can be gathered by an electrode. Scientists from the same group have now established that the electron-hole pairs also be in motion between the nanoparticles as free charges. For this purpose, they linked nanoparticles by utilizing very small molecules to make them thickly clustered while remaining isolated from each other. The nanoparticles are clustered closely to assist every single solar light particle imbibed by the solar cell induces electron movement.
Source: http://tudelft.nl/