Influence of the AlN interlayer thickness on the photovoltaic properties of in-rich AlInN on Si heterojunctions deposited by RF sputtering
S. Valdueza-Felip,
A. Núñez-Cascajero,
R. Blasco,
D. Montero,
L. Grenet,
M. de la Mata,
S. Fernández,
L. Rodríguez-De Marcos,
S. I. Molina,
J. Olea,
F. B. Naranjo
Affiliations
S. Valdueza-Felip
Photonics Engineering Group, University of Alcalá, 28871 Alcalá de Henares, Spain
A. Núñez-Cascajero
Photonics Engineering Group, University of Alcalá, 28871 Alcalá de Henares, Spain
R. Blasco
Photonics Engineering Group, University of Alcalá, 28871 Alcalá de Henares, Spain
D. Montero
Applied Physics Dept. III, University Complutense of Madrid, 28040 Madrid, Spain
L. Grenet
CEA-Grenoble, LITEN, and University Grenoble Alpes, 38000 Grenoble, France
M. de la Mata
Institute of Electron Microscopy and Materials, Dept. of Materials Science and I. M. and Q. I, Faculty of Sciences, University of Cádiz, 11510 Puerto Real, Spain
S. Fernández
Research Centre for Energy, Environment and Technology, 28040 Madrid, Spain
L. Rodríguez-De Marcos
Thin Film Optics Group, Optics Institute–CSIC, 28006 Madrid, Spain
S. I. Molina
Institute of Electron Microscopy and Materials, Dept. of Materials Science and I. M. and Q. I, Faculty of Sciences, University of Cádiz, 11510 Puerto Real, Spain
J. Olea
Applied Physics Dept. III, University Complutense of Madrid, 28040 Madrid, Spain
F. B. Naranjo
Photonics Engineering Group, University of Alcalá, 28871 Alcalá de Henares, Spain
We report the influence of the AlN interlayer thickness (0-15 nm) on the photovoltaic properties of Al0.37In0.63N on Si heterojunction solar cells deposited by radio frequency sputtering. The poor junction band alignment and the presence of a 2-3 nm thick amorphous layer at the interface mitigates the response in devices fabricated by direct deposition of n-AlInN on p-Si(111). Adding a 4-nm-thick AlN buffer layer improves the AlInN crystalline quality and the interface alignment leading to devices with a conversion efficiency of 1.5% under 1-sun AM1.5G illumination. For thicker buffers the performance lessens due to inefficient tunnel transport through the AlN. These results demonstrate the feasibility of using In-rich AlInN alloys deposited by radio frequency sputtering as novel electron-selective contacts to Si-heterojunction solar cells.
