Record performance of Dutch processed crystalline silicon solar cell

News - 10 November 2017 - Communication

At the Dutch national PV conference "Sunday" in Bussum on the 8th of November 2017 Prof. Miro Zeman from Delft University of Technology (TU Delft) presented a crystalline silicon solar cell with the conversion efficiency of 23.0%. This is the highest efficiency of crystalline silicon solar cell fully processed in The Netherlands. 

Dr. Isabella and Prof. Weeber are leading the team in the Photovoltaic Materials and Devices group at TU Delft that develops high-efficiency crystalline silicon solar cells using new architectures for enhancing light absorption and minimizing recombination of photo-generated carriers. 

This record performance was achieved with a solar-cell architecture in which both electrodes are placed at the back side of the solar cell. This architecture is known as "interdigitated back contacted (IBC)" solar cell. Advanced computer modelling was used to design the optimal thickness of supporting layers and the layout of interdigitated back contacts. A thin silicon oxide layer combined with doped polycrystalline silicon layers were developed for passivation of the back surface of silicon and selective extraction and collection of charged carriers. The development and optimization of supporting layers and the fabrication of solar cells was carried in clean rooms of Else Kooi Laboratory (EKL) of TU Delft.

In order to achieve this performance, the front surface of silicon wafer was textured. The surface texture was optimally designed in order to obtain both the excellent passivation of surface defects and at the same time an enhanced light absorption in silicon absorber. The development of high-efficiency crystalline silicon solar cells is carried out in several projects. In these projects the PVMD group works together with several academic, research and industrial partners such as Eindhoven University of Technology, ECN and Solliance, and Tempress, Levitech, Exasun, and SolMates.




Figure: Schematic structure of an IBC solar cell with passivating thin layer of SiO2 and carrier-selective doped polycrystalline silicon layers. FSF means Front Surface Field.

Dr. Guangtao Yang from the PVMD group with the record solar cells.