TY - JOUR
T1 - High-efficiency AlGaInP solar cells grown by molecular beam epitaxy
AU - Faucher, J.
AU - Sun, Y.
AU - Jung, D.
AU - Martin, D.
AU - Masuda, T.
AU - Lee, M. L.
N1 - The authors acknowledge funding from the ARPA-E FOCUS program under Award No. DE-AR0000508 and program manager Dr. Michael Haney. T.M. acknowledges the support of Toyota Motor Corporation. D. Martín acknowledges the support from the Spanish Ministerio de Educación, Cultura y Deporte through the José Castillejo program (CAS14-00479). The shared facilities were supported by the Yale Institute for Nanoscience and Quantum Engineering and NSF MRSEC DMR 1119826.
PY - 2016/10/24
Y1 - 2016/10/24
N2 - AlGaInP is an ideal material for ultra-high efficiency, lattice-matched multi-junction solar cells grown by molecular beam epitaxy (MBE) because it can be grown lattice-matched to GaAs with a wide 1.9-2.2 eV bandgap. Despite this potential, AlGaInP grown by molecular beam epitaxy (MBE) has yet to be fully explored, with the initial 2.0 eV devices suffering from poor performance due to low minority carrier diffusion lengths in both the emitter and base regions of the solar cell. In this work, we show that implementing an AlGaInP graded layer to introduce a drift field near the front surface of the device enabled greatly improved internal quantum efficiency (IQE) across all wavelengths. In addition, optimizing growth conditions and post-growth annealing improved the long-wavelength IQE and the open-circuit voltage of the cells, corresponding to a 3× increase in diffusion length in the base. Taken together, this work demonstrates greatly improved IQE, attaining peak values of 95%, combined with an uncoated AM1.5G efficiency of 10.9%, double that of previously reported MBE-grown devices.
AB - AlGaInP is an ideal material for ultra-high efficiency, lattice-matched multi-junction solar cells grown by molecular beam epitaxy (MBE) because it can be grown lattice-matched to GaAs with a wide 1.9-2.2 eV bandgap. Despite this potential, AlGaInP grown by molecular beam epitaxy (MBE) has yet to be fully explored, with the initial 2.0 eV devices suffering from poor performance due to low minority carrier diffusion lengths in both the emitter and base regions of the solar cell. In this work, we show that implementing an AlGaInP graded layer to introduce a drift field near the front surface of the device enabled greatly improved internal quantum efficiency (IQE) across all wavelengths. In addition, optimizing growth conditions and post-growth annealing improved the long-wavelength IQE and the open-circuit voltage of the cells, corresponding to a 3× increase in diffusion length in the base. Taken together, this work demonstrates greatly improved IQE, attaining peak values of 95%, combined with an uncoated AM1.5G efficiency of 10.9%, double that of previously reported MBE-grown devices.
UR - https://www.scopus.com/pages/publications/84993982711
UR - https://www.scopus.com/pages/publications/84993982711#tab=citedBy
U2 - 10.1063/1.4965979
DO - 10.1063/1.4965979
M3 - Article
AN - SCOPUS:84993982711
SN - 0003-6951
VL - 109
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 17
M1 - 172105
ER -