Flexible thin-film InAs/GaAs quantum dot solar cells

Thin-film InAs/GaAs quantum dot (QD) solar cells on mechanically flexible plastic films are fabricated. A 4.1-μm-thick compound semiconductor photovoltaic layer grown on a GaAs substrate is transferred onto a plastic film through a low-temperature bonding technique. We also fabricate thin-film InAs/GaAs quantum dot solar cells on Si substrates, as alternative low-cost, lightweight, robust substrates. The open-circuit voltages of the thin-film cells on plastic and Si substrates are equal to that of the as-grown bulk cell on a GaAs substrate, indicating that no material degradation occurs during our bond-and-transfer process.