TY - GEN
T1 - Progress of inverted metamorphic III-V solar cell development at Spectrolab
AU - Yoon, Hojun
AU - Haddad, Moran
AU - Mesropian, Shoghig
AU - Yen, Jason
AU - Edmondson, Kenneth
AU - Law, Daniel
AU - King, Richard R.
AU - Bhusari, Dhananjay
AU - Boca, Andreea
AU - Karam, Nasser H.
PY - 2008
Y1 - 2008
N2 - Inverted metamorphic (IMM) solar cells based on III-V materials have the potential to achieve solar conversion efficiencies that are significantly higher than today's state of the art solar cells which are based on the 3-junction GaInP/GaInAs/Ge design. The 3J IMM device architecture based on (Al)GaInP/GaInAs/GaInAs, for example, allows for a higher voltage solar cell by replacing the low bandgap Ge (0.67 eV) from the conventional 3J structure with the higher bandgap (∼1 eV) metamorphic GaInAs. The inverted growth simply allows the lattice-matched junctions (i.e., (Al)GaInP/GaInAs) to be grown first on the growth substrate, thereby minimizing or shielding them from the defects that arise from the metamorphic layers. Spectrolab has demonstrated 30.5% AM0 efficiency based on the 3J IMM cell architecture grown on a Ge substrate, with Voc = 2.963V, Jsc = 16.9 mA/cm2, and FF = 82.5%. In addition, 4J IMM cells have been demonstrated with Voc of 4.072 V and AM0 efficiency approaching 25%. With additional development, demonstrating 33% AM0 efficiency is expected in the near future. However, the IMM devices demand more complex processing requirements than conventional solar cells, and we demonstrate the capability to fabricate large area solar cells from standard Ge solar cell substrates.
AB - Inverted metamorphic (IMM) solar cells based on III-V materials have the potential to achieve solar conversion efficiencies that are significantly higher than today's state of the art solar cells which are based on the 3-junction GaInP/GaInAs/Ge design. The 3J IMM device architecture based on (Al)GaInP/GaInAs/GaInAs, for example, allows for a higher voltage solar cell by replacing the low bandgap Ge (0.67 eV) from the conventional 3J structure with the higher bandgap (∼1 eV) metamorphic GaInAs. The inverted growth simply allows the lattice-matched junctions (i.e., (Al)GaInP/GaInAs) to be grown first on the growth substrate, thereby minimizing or shielding them from the defects that arise from the metamorphic layers. Spectrolab has demonstrated 30.5% AM0 efficiency based on the 3J IMM cell architecture grown on a Ge substrate, with Voc = 2.963V, Jsc = 16.9 mA/cm2, and FF = 82.5%. In addition, 4J IMM cells have been demonstrated with Voc of 4.072 V and AM0 efficiency approaching 25%. With additional development, demonstrating 33% AM0 efficiency is expected in the near future. However, the IMM devices demand more complex processing requirements than conventional solar cells, and we demonstrate the capability to fabricate large area solar cells from standard Ge solar cell substrates.
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U2 - 10.1109/PVSC.2008.4922599
DO - 10.1109/PVSC.2008.4922599
M3 - Conference contribution
AN - SCOPUS:84879718078
SN - 9781424416417
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
BT - 33rd IEEE Photovoltaic Specialists Conference, PVSC 2008
T2 - 33rd IEEE Photovoltaic Specialists Conference, PVSC 2008
Y2 - 11 May 2008 through 16 May 2008
ER -