title: Superacid Passivation of Crystalline Silicon Surfaces.
abstract: The reduction of parasitic recombination processes commonly occurring within the silicon crystal and at its surfaces is of primary importance in crystalline silicon devices, particularly in photovoltaics. Here we explore a simple, room temperature treatment, involving a nonaqueous solution of the superacid bis(trifluoromethane)sulfonimide, to temporarily deactivate recombination centers at the surface. We show that this treatment leads to a significant enhancement in optoelectronic properties of the silicon wafer, attaining a level of surface passivation in line with state-of-the-art dielectric passivation films. Finally, we demonstrate its advantage as a bulk lifetime and process cleanliness monitor, establishing its compatibility with large area photoluminescence imaging in the process.
authors.affiliation: Electrical Engineering and Computer Sciences, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Bullock
authors.affiliation: Electrical Engineering and Computer Sciences, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kiriya
authors.affiliation: Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Grant
authors.affiliation: Department of Materials Science and Engineering, University of Texas, Dallas , Richardson, Texas 75080, United States.
authors.forename: Angelica
authors.initials: A
authors.lastname: Azcatl
authors.affiliation: Electrical Engineering and Computer Sciences, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Hettick
authors.affiliation: Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: Teng
authors.initials: T
authors.lastname: Kho
authors.affiliation: Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: Pheng
authors.initials: P
authors.lastname: Phang
authors.affiliation: Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: Hang C
authors.initials: HC
authors.lastname: Sio
authors.affiliation: Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: Di
authors.initials: D
authors.lastname: Yan
authors.affiliation: Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Macdonald
authors.affiliation: Department of Materials Science and Engineering, University of Texas, Dallas , Richardson, Texas 75080, United States.
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Quevedo-Lopez
authors.affiliation: Department of Materials Science and Engineering, University of Texas, Dallas , Richardson, Texas 75080, United States.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Wallace
authors.affiliation: Research School of Engineering, The Australian National University (ANU) , Canberra, Australian Capital Territory 2602, Australia.
authors.forename: Andres
authors.initials: A
authors.lastname: Cuevas
authors.affiliation: Electrical Engineering and Computer Sciences, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Ali
authors.initials: A
authors.lastname: Javey
keywords: bulk lifetime; photoluminescence imaging; photovoltaics; silicon; surface passivation