Light Management and Interface engineering for highly Efficient and ultra-Thin CIGS solar cells
The LIMIET project is a collaborative project with the TU Delft, TU of Eindhoven and TNO/Solliance (where the PV solar cells are fabricated). The objective of the project is to maintain high-efficient copper-indium-gallium-selenide (CIGS) solar cells, while strongly reducing the thickness of the absorber layer, from a 2 micrometer to below 500 nanometer.
Focus points are changing materials/ interfaces to reduce parasitic losses at the back contact (primarily with atomic layer deposition at TU of Eindhoven) and using advanced light management techniques to reduce losses in the front of the solar cell (by texturing and fabrication of multi-junction devices, primarily at TU Delft).
The focus of this PhD project is twofold:
- Enhance the optical path length while limiting the physical thickness. This can be done, using advanced light management techniques, such as texturing TCO layers or the glass substrates (as in the SEM image below). The wide craters can efficiently scatter the (infra)red light, while there are no sharp valleys, preventing damage during the growth of the sequential layers.
- Fabrication of multi-junction cells. Multi-junction devices utilize the solar spectrum more efficiently, (reducing thermalisation/below-bandgap losses), and the parasitic losses usually induced by the window layers of the regular CIGS solar cells, such as CdS and AZO. The SEM image below shows a a-Si:H/CIGS hybrid tandem cell.
- Santbergen, R.; Blanker, J.; Dhathathreyan, A.; Tan, H.; Smets, A.H.M.; Zeman, M., "Towards Lambertian internal light scattering in solar cells using coupled plasmonic and dielectric nanoparticles as back reflector", Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th, 16-21 June 2013, doi: 10.1109/PVSC.2013.6744092
- MSc thesis: "TiO2 nanoparticles as back reflector in thin-film solar cells", TU Delft (2013)
- P. Babal, J. Blanker, R. Vasudevan, A. H. M. Smets, and M. Zeman (2012). "Microstructure analysis of n-doped µc-SiOx:H reflector layers and their implementation in stable a-Si:H p-i-n junctions", 38th IEEE Photovoltaic Specialists Conference (PVSC) Proceeding