Single-junction silicon solar cells are reaching the limit of their efficiency. To fabricate solar cells with higher efficiencies, tandem devices are being developed, which have multiple junctions to utilise a greater proportion of the solar spectrum. One method of combining multiple junctions is in a silicon/singlet fission tandem device.

In this structure the low energy photons are collected by the silicon cell, with minimal energy losses. The high energy photons are absorbed in an organic layer which undergoes singlet fission to create two excitons from each photon. These two excitons are transferred to the silicon cell and contribute twice as much energy from the photon, compared to a conventional single-junction solar cell. 

A crucial aspect of this device is the interlayer between the silicon and organic material. This layer must passivate the silicon surface (terminate surface defects) to ensure the underlying silicon device maintains its high efficiency, while simultaneously allowing the transfer of excitons from the organic material into the silicon. This project will involve fabrication and testing potential interlayer materials to find optimum conditions to maximise the efficacy of both exciton transfer and silicon defect passivation. 


Photovoltaic and Renewable Energy Engineering

Research Area

Silicon solar cells | Surface passivation | High efficiency solar cells

The student will work closely with Shona McNab who specialises in characterising silicon surface passivation and have the oversight of Alison Ciesla and other members of the OMEGA silicon team.

Experimental work will involve fabricating samples using atomic layer deposition and characterising the samples using a variety of optical and electrical techniques. The project will make use of the world class facilities in SPREE, the School of Physics and MWAC.

The student undertaking this project will:

  • Develop a deep understanding of the mechanisms behind silicon surface passivation and characterisation techniques used extensively in the PV industry. 
  • Learn about advanced characterisation techniques for measuring singlet fission and exciton transfer into silicon. 
  • Learn design experiments and data analysis. The outputs of this research may lead to potential journal/conference publications.