ANALYSIS OF SELECTIVE TEXTURING IN THE FORMATION OF P+ EMITTERS WITH LASER IRRADIATION FOR N-PERC SOLAR CELLS
DOI:
https://doi.org/10.59627/cbens.2024.2384Keywords:
Selective emitter, Laser diffusion, Boron emitterAbstract
This article presents the processing and analysis of boron-doped emitters, formed through laser diffusion and selective texture etching. The samples were produced through two manufacturing processes, denoted as A and B, employing three distinct laser configurations for boron diffusion. In process A, or selective texture etching, boron diffusion occurred before the anisotropic etching to form a textured surface. This process involved the examination of four texturing times. In process B, surface etching was carried out before laser boron diffusion. The devices were analyzed through optical microscopy, sheet resistance measurement (RSQ), and minority carrier lifetime (τ). Samples developed by process B (the control process) exhibited sheet resistance values in the range of 26 – 28 Ω/sq, while samples developed by process A (selective texturing process) showed an increase in R SQ values, in the order of 53 - 60 Ω/sq. Through the analysis of minority carrier lifetime, no significant difference in damage caused by different laser configurations was observed. When analyzing the percentage difference between the values of minority carrier lifetime in regions where laser diffusion occurred (fingers) and regions without diffusion (between fingers), a higher reduction in τ was observed in samples from the control process, with pre-laser texturing (process B). These results indicate that the use of an anisotropic etching post-laser diffusion partially reduces the damage generated during processing.
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