Characterization of the rear surface roughness of wet chemical polished industrial-type solar cells

Abstract

PERC solar cells require smooth rear surfaces to reduce surface recombination and increase cell efficiency. State of the art surface roughness is defined solely by the polishing etch depth. However the initial texture height can vary, therefore there is no universal definition of roughness. In this work we study the rear surface roughness of industrial p-type solar cells. Different roughness parameters are presented and compared to each other and the suitability of reflection as an inline process control parameter will be shown. Subsequently, the effects of rear side roughness on the passivation quality and thus minority carrier lifetime will be discussed. A roughness optimum for multi-crystalline samples is found and therefore there is an optimal reflectance that can be controlled while processing

Comparison of the Electrical Properties of PERC Approach Applied to Monocrystalline and Multicrystalline Silicon Solar Cells

“…International Journal of Photoenergy 5 some researches [13]. Hydrogen existed in dielectric layers in the form of Si-H or N-H bond.…”

Optical Simulation and Analysis of Iso-textured Silicon Solar Cells and Modules Including Light Trapping

“…1b). The implemented rear surface morphology corresponds to a single-sided etched-back surface of textured mc-Si wafers (6 m etch-back) [16] and was measured using a confocal microscope. Within the titled-mirrors approach, the amplitude of the light reflected at the rear surface is calculated again using the transfer matrix formalism and assuming 10 nm AlO x covered by 100 nm SiN x and a thick aluminum layer.…”