Lefteris research interests encompass the field of photovoltaics and solar energy conversion. In particular he is interested in developing light harvesting and photon management structures for applications in high efficiency low cost solar cells. Light harvesting structures can be fabricated based on ultra-thin film organic architectures for increased absorption of light and better solar energy utilization. Efficient spectral management of the solar spectrum can be applied to existing solar cell devices towards lower cost of solar electricity.

We have a range of projects, although funding is currently not available. We welcome applications from self-funded students or from students seeking external funding. Training will be provided in Time Resolved Fluorescence Spectroscopy, and Lifetime Imaging using Confocal Microscopy for the application in light harvesting structures.

Luminescent Solar Concentrators

Our research involves the development of Luminescent Solar Concentrators (LSC) and luminescence down shifting (LDS) structures for efficient spectral management and light trapping. An LSC usually consists of a flat plate, doped with a luminescent species, which absorbs the incident sunlight (direct or diffuse). A large fraction of the emitted light is then trapped within the collector by total internal reflection (TIR) and is directed to a solar cell at the edge of the collector where the remaining edges of the collector can be covered by mirrors. 

Light Harvesting 

The term “light harvesting” describes a process which enhances the absorption cross section of the photosynthetic reaction complex by excitation energy transfer, often called resonance energy transfer. The proposed research aims to develop a light harvesting framework as a means of energy collection and sensitisation of silicon solar cells. Experimental results have revealed the existence of a similar energy transfer mechanism between a molecule and a semiconductor, as demonstrated by quenching of molecular fluorescence in proximity to silicon for Langmuir-Blodgett (LB) films. We use Time Resolved Fluorescence Spectroscopy and Fluorescence Lifetime Imaging Microscopy on the light harvesting structures to determine energy transfer and photon collection efficiencies.