Master projects/internships - Leuven | More than two weeks ago
Make and test your own silicon solar cells
The photovoltaic (PV) industry at present is dominated by the p-PERC silicon solar cell technology, which has an average efficiency of 22 % in production. The efficiency of today’s PERC technology is inherently limited by carrier recombination at the metal-semiconductor contacts. Advanced contacting approaches have to be adopted to enable further efficiency increases in silicon solar cells. This is achievable by applying the so-called carrier-selective passivating contacts to silicon solar cells. Already a few different schemes for this type of contact exist.
This internship/Master thesis work would focus on the n+ poly-silicon/SiO2 type of passivating contact, which could eventually enable solar cells with efficiencies above 24 %. The poly-Si, which needs to be compatible with screen-printing (an industrial metallization technology), and thus, at least 80 nm to 100 nm thick, is to be developed by solid-phase crystallization (SPC) of amorphous Si (a-Si) grown using plasma-enhanced chemical vapour deposition (PECVD). However, SPC of a-Si thin films above 20 nm is challenging because they may blister during deposition or crystallisation. To this end, techniques like alloying the a-Si film with C or O will be explored for fabricating thick, blister-resistant PECVD Si films and eventually blister-free n+ poly-silicon films. Such alloying could also offer the added advantage of minimizing parasitic optical absorption in the poly-Si layer by widening the bandgap of the alloyed poly-silicon. A multitude of techniques are available to characterize solar cell test structures and material properties. Some of the main characterization methods applicable to this work are spectroscopic ellipsometry (SE), elastic recoil detection (ERD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy (RS), photo-conductance decay (PCD) measurement, secondary-ion mass spectroscopy (SIMS) and transfer-length measurement (TLM). The larger goal of this work is to develop a blister-free, screen-printing compatible n+ poly-Si/SiO2 contact having state-of-the-art passivation and contact resistance.
Type of project: Internship
Duration: 9 months
Master's degree: Master of Engineering Science; Master of Engineering Technology; Master of Science
Master program: Energy
Supervising scientist: For further information or for application, please contact Rajiv Sharma (Rajiv.Sharma @imec.be).