Akce ČVUT

Tom Markvart: Silicon and light: thermodynamics, solar cells and nanotechnology

24.03.2014   16:15

Silicon and light: thermodynamics, solar cells and nanotechnology

Tom Markvart
Solar Energy Laboratory, Engineering Sciences,
University of Southampton, Southampton, UK.

Efficient capture of sunlight remains one of the great challenges to photovoltaics today. This is particularly so for the dominant photovoltaic material ? crystalline silicon ? which, as an indirect-bandgap semiconductor, needs a thickness of several hundred micrometers for efficient operation. This talk will give an overview of the principal concepts that are currently being considered to enhance light capture by the solar cell, bringing together two main ideas of thought that underpin the current status of the field. The first, based on thermodynamics, makes use of light trapping where the photon path length within a structure is extended by virtue of a stochastic photon distribution inside a dielectric or weakly absorbing semiconductor. The second approach rests on the use of sub-wavelength or nanoscale structures which allow electromagnetic energy injection into very thin semiconductor layers, by a direct interaction with the evanescent field of the trapped modes or via the near field of an intermediate dipole absorber or scatterer. We shall discuss the theoretical foundations against the background of experimental results based on fluorescence measurements for molecular layers deposited on bulk wafers, glass or thin crystalline silicon layers by spin coating, in the form of Langmuir-Blodgett films, or directly anchored to silicon by covalent bonding

Místo konání

T2:D3-209

Kontaktní osoba

Pavel Ripka