TY - GEN
T1 - High indium composition (>20%) InGaN EPI-layers on ZnO substrates for very high efficiency solar cells
AU - Melton, Andrew
AU - Jampana, Balakrishnam
AU - Li, Nola
AU - Jamil, Muhammad
AU - Zaidi, Tahir
AU - Fenwick, William
AU - Opila, Robert
AU - Honsberg, Christiana
AU - Ferguson, Ian
PY - 2009
Y1 - 2009
N2 - In this report we present recent results for MOCVD growth of high indium content InGaN films on ZnO substrates. Growth was attempted on both bulk ZnO as well as ZnO epilayers grown on sapphire by MOCVD. ZnO is an attractive alternative substrate for III-Nitrides because of its superior lattice match: specifically ZnO is perfectly matched with In0.18Ga0.82N and low cost of substrates. Stable InGaN films with >18% indium were achieved on the bulk substrates and were characterized by HRXRD, PL, and optical transmission. Varying the growth parameters - primarily growth temperature and In/(In + Ga) flow ratio - was found to affect the optical and structural properties of the films. By growing on a better matched substrate the high indium composition InGaN epitaxial films experience less strain and can therefore be grown thicker without creating relaxation-induced extended crystal defects. This is important, as high indium content InGaN films cannot be grown on GaN thick enough for full above-bandgap absorption without introducing detrimental extended crystal defects. This limitation is thought to be a limiting factor in the achievable ISC in InGaN solar cells.
AB - In this report we present recent results for MOCVD growth of high indium content InGaN films on ZnO substrates. Growth was attempted on both bulk ZnO as well as ZnO epilayers grown on sapphire by MOCVD. ZnO is an attractive alternative substrate for III-Nitrides because of its superior lattice match: specifically ZnO is perfectly matched with In0.18Ga0.82N and low cost of substrates. Stable InGaN films with >18% indium were achieved on the bulk substrates and were characterized by HRXRD, PL, and optical transmission. Varying the growth parameters - primarily growth temperature and In/(In + Ga) flow ratio - was found to affect the optical and structural properties of the films. By growing on a better matched substrate the high indium composition InGaN epitaxial films experience less strain and can therefore be grown thicker without creating relaxation-induced extended crystal defects. This is important, as high indium content InGaN films cannot be grown on GaN thick enough for full above-bandgap absorption without introducing detrimental extended crystal defects. This limitation is thought to be a limiting factor in the achievable ISC in InGaN solar cells.
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U2 - 10.1109/PVSC.2009.5411216
DO - 10.1109/PVSC.2009.5411216
M3 - Conference contribution
AN - SCOPUS:77951565307
SN - 9781424429509
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
SP - 1123
EP - 1126
BT - 2009 34th IEEE Photovoltaic Specialists Conference, PVSC 2009
T2 - 2009 34th IEEE Photovoltaic Specialists Conference, PVSC 2009
Y2 - 7 June 2009 through 12 June 2009
ER -