Optical modelling of the front surface for honeycomb-textured silicon solar cells

Abstract

In this study we assess the reproducibility of the honeycomb texturing process, and we compare experimental values to a simulation. Our results show that the honeycomb-texture can be simulated with the OPAL program. It calculates the losses of any angle of incidence, where the short computation time is achieved by decoupling the ray tracing from the Fresnel equation. We investigate various surface morphologies and their impact on reflection values. The samples were etched at different etching times, whereby the honeycomb geometries were changed. Using our optimal acid etching solution ratio, we are able to fabricate a HC-texture with a reflectivity of R = 19.4 % (ω = 85°). Between the simulation values and those of the measurement, we see a difference of R = 0.3 %abs. This small deviation causes the relatively inaccuracies of the simulation and the measured samples. The focus is to simulate the different honeycomb structures and compare the values with the experimental values.