Scientists from Fraunhofer ISE intend to make use of epitaxially grown p-type silicon wafers as TOPCon rear emitter (TOPCore) photo voltaic cells with the purpose of lowering manufacturing prices and carbon footprint. They declare that this mix paves the best way for TOPCore units with greater than 25% effectivity.
Germany’s Fraunhofer Institute for Photo voltaic Vitality Programs (ISE) has proposed the usage of epitaxially grown p-type silicon wafers in TOPCon rear emitter (TOPCore) photo voltaic cells, combining tunnel oxide passivated contact (TOPCon) know-how in a rear emitter as an alternative of the entrance. – aspect pn junction.
Epitaxially grown p-type wafers, additionally referred to as “EpiWafers,” provide a low-cost and low-carbon materials for photo voltaic cells, offering increased voltages and fill charges. matter in comparison with cells with a front-side accumulating emitter.
Epitaxially grown p-type wafers, additionally referred to as “EpiWafers,” provide a low-cost and low-carbon materials for photo voltaic cells, offering increased voltages and fill charges. matter in comparison with cells with a front-side accumulating emitter.
The scientists grew p-type Cz-Si wafers with a resistivity of two.5 Ω cm and a diameter of 150 mm via a chemical vapor deposition (CVD) batch reactor at atmospheric strain. They then chemically cleaned and passivated the wafers with a floor passivation layer product of aluminum oxide (Al2O3) deposited by plasma-assisted atomic layer deposition (ALD) at 180 C for 78 cycles, leading to in 10 nm thick layers on each side.
“The ensuing pattern set consists of EpiRef wafers with a remaining thickness of 110 μm and three totally different base resistivities of three, 14, and 100 Ω cm,” they mentioned.
Making use of the entrance finger grid design to all EpiRef wafers, the workforce noticed that every of the three units might probably obtain energy conversion effectivity exceeding 25%. In addition they famous that the presence of iron (Fe), chromium monoboride (CrB), and Boron (BO) defects in EpiWafers didn’t have an effect on cell efficiency, indicating the top quality and purity of epitaxially grown wafers.
“In our case, these structural defects, originating from epitaxial progress, could be averted through the use of a distinct susceptor design,” the teachers mentioned. “Structural defect-free areas protect their wonderful materials high quality throughout high-temperature processing.”
They introduced a novel approach for making “Epitaxially Grown p-type Silicon Wafers Prepared for Cell Efficiencies Exceeding 25%,” which was lately printed in RRL Photo voltaic.
In April 2021, Fraunhofer ISE mentioned it had achieved an effectivity of 26.1% for a TOPCore photo voltaic cell.
“Primarily based on a scientific simulation-based evaluation, we have been capable of derive some elementary design guidelines for future high-efficiency silicon photo voltaic cells with better than 26% effectivity,” Stefan Glunz, division director of photovoltaics analysis at Fraunhofer ISE, mentioned on the time. “The 2-sided contacted photo voltaic cells have the potential to realize efficiencies as much as 27 p.c and thus surpass the earlier world file for silicon photo voltaic cells.”
This content material is protected by copyright and will not be reused. If you wish to cooperate with us and need to reuse a few of our content material, please contact: [email protected].
