title: A direct thin-film path towards low-cost large-area III-V photovoltaics.
abstract: III-V photovoltaics (PVs) have demonstrated the highest power conversion efficiencies for both single- and multi-junction cells. However, expensive epitaxial growth substrates, low precursor utilization rates, long growth times, and large equipment investments restrict applications to concentrated and space photovoltaics (PVs). Here, we demonstrate the first vapor-liquid-solid (VLS) growth of high-quality III-V thin-films on metal foils as a promising platform for large-area terrestrial PVs overcoming the above obstacles. We demonstrate 1-3 μm thick InP thin-films on Mo foils with ultra-large grain size up to 100 μm, which is ~100 times larger than those obtained by conventional growth processes. The films exhibit electron mobilities as high as 500 cm²/V-s and minority carrier lifetimes as long as 2.5 ns. Furthermore, under 1-sun equivalent illumination, photoluminescence efficiency measurements indicate that an open circuit voltage of up to 930 mV can be achieved, only 40 mV lower than measured on a single crystal reference wafer.
authors.affiliation: Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, USA.
authors.forename: Rehan
authors.initials: R
authors.lastname: Kapadia
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Yu
authors.forename: Hsin-Hua H
authors.initials: HH
authors.lastname: Wang
authors.forename: Maxwell
authors.initials: M
authors.lastname: Zheng
authors.forename: Corsin
authors.initials: C
authors.lastname: Battaglia
authors.forename: Mark
authors.initials: M
authors.lastname: Hettick
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kiriya
authors.forename: Kuniharu
authors.initials: K
authors.lastname: Takei
authors.forename: Peter
authors.initials: P
authors.lastname: Lobaccaro
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Beeman
authors.forename: Joel W
authors.initials: JW
authors.lastname: Ager
authors.forename: Roya
authors.initials: R
authors.lastname: Maboudian
authors.forename: Daryl C
authors.initials: DC
authors.lastname: Chrzan
authors.forename: Ali
authors.initials: A
authors.lastname: Javey