Investigation of antimony diffusion for a local back surface field with laser-fired contacts in crystalline silicon solar cells

Laser processing of materials for renewable energy applications

“…Antimony (Sb) was laser doped into n-type crystalline silicon by Takahashi et al 34 in 1985 to form a low resistance ohmic contact, but unlike the laser-fi ring process developed by Fraunhofer, there was no dielectric passivation layer on the surface of the silicon wafer. More recently, Song et al 35 laser fi red Sb through a thermal oxide into n-type Si to form localized back-surface fi eld contacts, and they fabricated solar cells with effi ciencies as high as 17.2%. In even more recent work, He et al 36 laser fi red Al/Sb stacked layers through either silicon nitride or p-type amorphous silicon to make ohmic contacts to n-type Si, and they demonstrated effi ciencies as high as 16.9% in interdigitated back-contact silicon heterojunction solar cells.…”

Laser‐fired contact for n‐type crystalline Si solar cells

“…Laser-fired contacts (LFCs), first proposed by Schneiderlochner et al at Fraunhofer [1], are an elegant way to develop the rear point contact of crystalline silicon solar cells together with a well-passivated back surface. Since their inception, electrical properties, local composition, lifetime impact, and device properties of LFC have been widely studied [1][2][3][4][5][6][7][8]. However, most studies focus on Al LFC on p-type Si to form the base contact or n-type Si to form the emitter, respectively [3], while there are very few publications applying LFC to obtain the ohmic base contact for n-type Si wafers [4][5][6].…”

“…Since their inception, electrical properties, local composition, lifetime impact, and device properties of LFC have been widely studied [1][2][3][4][5][6][7][8]. However, most studies focus on Al LFC on p-type Si to form the base contact or n-type Si to form the emitter, respectively [3], while there are very few publications applying LFC to obtain the ohmic base contact for n-type Si wafers [4][5][6]. To achieve a reproducible metallic ohmic contact with crystalline silicon requires doping of silicon at the metal/silicon interface to reduce the potential barrier width so that electron tunneling is possible [9].…”

Laser fired ohmic contacts in silicon using pulse modulated CW laser

“…But photolithography is expensive and is not a friendly process for large volume industrial production. The alternative method is to use laserfired contacts (LFC) of aluminium (Al) through the rear passivation layer [1][2][3][4][5].…”