Name: Arsalan Razzaq

Promotie / Defence

When: 25/08/2020 16:30
Language: en

Where: aula van de Tweede Hoofdwet, 01.02, Kasteelpark Arenberg 41, 3001 Heverlee

Promotor / Supervisor

Prof. dr. ir. Jozef Poortmans (promotor)

Samenvatting van het onderzoek / Summary of Research

The world is facing a climate crisis with the challenge of keeping the global temperature rise below 1.5 °C over the next decade for reversing its dire consequences. Concurrently, the ever-increasing electricity demand for domestic and industrial consumption has also stimulated growth in the renewables sector. Particularly, in the power generation sector, the market share of the crystalline-silicon (c-Si) photovoltaic (PV) technology has expanded rapidly in recent times with continual decline in module prices. Further efficiency improvements and cost reductions are necessary for enabling global terawatt-scale deployment of PV. These objectives can potentially be met by either fabricating c-Si solar devices on thinner wafers for curtailing cell-related costs and/or by realizing tandem devices (combination of perovskite and c-Si solar devices) for minimizing the system-level costs. Nevertheless, for both stated routes, the challenge is to ensure complete infrared light absorption in c-Si solar cells.

An advanced light absorption scheme, based on periodic inverse nanopyramid gratings, is theoretically known to effectively confine the weakly-absorbing light in a c-Si substrate. However, the expected performance boost by using diffraction gratings is yet to be demonstrated on working solar devices. This means that additional optical and electrical losses are present which have been overlooked in theoretical investigations. It is therefore the objective of the thesis to comprehensively evaluate the intrinsic and experimental constraints that are brought by the introduction of inverse nanopyramid gratings in c-Si solar devices. These limitations were thus systematically identified and tackled, allowing to demonstrate superior infrared light absorption with respect to the industry benchmark. Finally, beyond optical effects, the role of the nanoscale pyramid size in improving the electrical performance is explained.

Volledige tekst van het doctoraat / full text

Examencommissie / Board of examiners

Prof. dr. ir. Jozef Poortmans (promotor)
Prof. dr. Bart Demoen (chairman)
Prof. dr. ir. Johan Driesen (secretary)
Prof. dr. ir. Robert Pierre Mertens
Prof. dr. Andre Stesmans
Prof. dr. Olivier DEPARIS , Université de Namur
Prof. dr. Olindo Isabella , TU Delft
Dr. Valérie Depauw , IMEC