title: Investigation of Bismuth Triiodide (BiI3) for Photovoltaic Applications.
abstract: Guided by predictive discovery framework, we investigate bismuth triiodide (BiI3) as a candidate thin-film photovoltaic (PV) absorber. BiI3 was chosen for its optical properties and the potential for "defect-tolerant" charge transport properties, which we test experimentally by measuring optical absorption and recombination lifetimes. We synthesize phase-pure BiI3 thin films by physical vapor transport and solution processing and single-crystals by an electrodynamic gradient vertical Bridgman method. The bandgap of these materials is ∼1.8 eV, and they demonstrate room-temperature band-edge photoluminescence. We measure monoexponential recombination lifetimes in the range of 180-240 ps for thin films, and longer, multiexponential dynamics for single crystals, with time constants up to 1.3 to 1.5 ns. We discuss the outstanding challenges to developing BiI3 PVs, including mechanical and electrical properties, which can also inform future selection of candidate PV absorbers.
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Riley E
authors.initials: RE
authors.lastname: Brandt
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Kurchin
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Robert L Z
authors.initials: RL
authors.lastname: Hoye
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: Poindexter
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Mark W B
authors.initials: MW
authors.lastname: Wilson
authors.affiliation: University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Soumitra
authors.initials: S
authors.lastname: Sulekar
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Frances
authors.initials: F
authors.lastname: Lenahan
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Patricia X T
authors.initials: PX
authors.lastname: Yen
authors.affiliation: Colorado School of Mines , 1500 Illinois Street, Golden, Colorado 80401, United States.|National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States.
authors.forename: Vladan
authors.initials: V
authors.lastname: Stevanović
authors.affiliation: University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Nino
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Moungi G
authors.initials: MG
authors.lastname: Bawendi
authors.affiliation: Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Tonio
authors.initials: T
authors.lastname: Buonassisi