Screen-printed contacts with H-patterned n-type passivated emitter rear totally diffused solar cell and front-side boron selective emitter formed by wet chemical etching

Abstract

This paper presents the efficiency distribution of an n-type bifacial solar cell. In this work, the solar cells were produced by our standard cell fabrication process, which is very similar to the industrial line process. The best cell efficiency was 20.4%, and the average efficiency was 20.06%. The cell efficiency ranged between 19.9 and 20.4% and showed a narrow efficiency distribution. This paper also presents the development of a boron selective emitter (p + /p ++ ) n-type bifacial solar cell. In this work, the cells were fabricated using the standard cell fabrication process based on tube-furnace thermal diffusion employing liquid sources: BBr 3 for the front-side boron emitter and POCl 3 for the rear-side phosphorus backsurface field (BSF). The p + /p ++ structure was formed by screen-printing resist masking and wet chemical etching technology. Both the front-and rear-side electrodes were obtained by using screen-printed contacts with H-patterns. The cell efficiency with the selective boron emitter was almost the same as that with the homogeneous emitter; however, the V oc of the selective emitter solar cell was higher than that of the homogeneous emitter solar cell by 4.4 mV. Finally, we performed the recombination analysis of the completed cell.

Internal quantum efficiency mapping analysis for a >20%-efficiency n-type bifacial solar cell with front-side emitter formed by BBr3 thermal diffusion

“…Boron secondary ion mass spectrometry profiles can be seen elsewhere. 15) The saturation current density J 0,e was measured using the quasi-steady-state microwave photoconductance decay (QSS-uPCD) method. Al 2 O 3 was deposited by an O 3 -based thermal atomic layer deposition (ALD) method.…”

“…1 was fabricated, and a 0.4% improvement in the cell-conversion efficiency was obtained by modulating the front-side boron-emitter profile. 15) Recently, the cellconversion efficiency was improved to 19.6% by modulating the boron-depleted region on this type of cell structure. 16) Different dielectric layers (SiN x =SiO 2 , SiN x =Al 2 O 3 ) have been applied to achieve very effective passivation on the boron emitters, [17][18][19] and a SiN x =SiO 2 stack or thermal SiN x single layer was applied on the n-type surface.…”