AVS 60th International Symposium and Exhibition
    Energy Frontiers Focus Topic Tuesday Sessions
       Session EN-TuM

Paper EN-TuM9
A Direct Thin-Film Path towards Low-Cost Large-Area III-V Photovoltaics

Tuesday, October 29, 2013, 10:40 am, Room 101 A

Session: Energy Past, Present, and Future
Presenter: R. Kapadia, University of California, Berkeley
Authors: R. Kapadia, University of California, Berkeley
Z. Yu, University of California, Berkeley
A. Javey, University of California, Berkeley
Correspondent: Click to Email
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 mm thick InP thin-films on Mo foils with ultra-large grain size up to 100 mm, 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 with our films, only 40 mV lower than what we measure on a single crystal reference wafer.