Dr Johnson WONG

Dr Johnson WONG

Head of PV characterisation
SERIS, Singapore

Griddler 2.5 PRO: Modelling high efficiency solar cells with parameter database to calculate room for efficiency improvement

In research, pilot line or production line ramping, it is important to have a working model of each solar cell type so that the areas of efficiency improvement can be identified, in order to speed up the cell optimization process.  Griddler 2.5 PRO is a powerful solar cell finite element solver that models a solar cell down to the details of metallization grid pattern, print quality, edge isolation and passivation quality, front metal grid induced recombination, rear local contacts recombination and resistance, and rear silver pad recombination.  It also comes with a parameter database that allows the user to calculate the room for efficiency improvement with suitable process optimization or new technology adaptation.  In this talk, two examples of p-type localized BSF (LBSF) and n-type bifacial solar cell models will be presented, and various scenarios of efficiency improvement will be explored.


Johnson Wong is the head of PV characterisation at the Solar Energy Research Institute of Singapore (SERIS). He completed his PhD in photovoltaic engineering at UNSW in the area of thin-film silicon on glass solar cells. Since then he joined SERIS as a scientist, engaging in various research topics such as screen-printed and evaporated-metal all-back-contact solar cells, and a-Si:H/uc-Si:H c-Si heterojunction solar cells. His current work includes the development of photoluminescence and electroluminescence detection and analysis methods, application of solar cell reciprocity relations, and the study of the impacts of solar cell lateral non-uniformity and distributed resistances on device performance.  Johnson is the inventor of Griddler, a computer program that applies full area, two-dimensional finite element analysis (FEA) to solar cells with arbitrary metallisation geometries.