Title :
Passivation of different black silicon surfaces by ALD deposited Al2O3
Author :
Otto, M. ; Kroll, Mark ; Kasebier, Thomas ; Xiaopeng Li ; Gesemann, Benjamin ; Fuchsel, Kevin ; Ziegler, Jens ; Sprafke, Alexander N. ; Wehrspohn, Ralf B.
Author_Institution :
FG μMD, Martin-Luther-Univ. (MLU), Halle, Germany
Abstract :
Optical properties of black silicon (b-Si) can be tailored to minimize reflection losses to less than 0.6 % between 300-1000 nm and to improve the absorption at the silicon band-edge by light-trapping. Recently, metal assisted wet-chemically etched (MACE) b-Si was exploited to fabricate high efficiency (18.2 %) solar cells with surface passivation by thermal SiO2 and recombination velocities (SRV) of ~100 cm/s [1]. We compare surface passivation performance of ALD-Al2O3 on different dry and wet etched nanostructures. SRVs ≤ 8 cm/s on bifacially black 1 Ωcm p-type Si FZ wafers were measured. This technological advance will enable higher efficiencies for various PV-cell concepts.
Keywords :
alumina; atomic layer deposition; carrier lifetime; elemental semiconductors; passivation; silicon compounds; solar cells; ALD; Al2O3; FZ wafers; MACE; PV-cell concepts; SiO2; atomic layer deposition; black silicon surfaces; dry etched nanostructures; light trapping; metal assisted wet-chemically etched; optical properties; recombination velocities; reflection losses; silicon band edge; solar cells; surface passivation; wet etched nanostructures; Absorption; Aluminum oxide; Iterative closest point algorithm; Silicon; Surface cleaning; Surface morphology; Al2O3; atomic layer deposition; black silicon; charge carrier lifetime; passivation;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th
Conference_Location :
Tampa, FL
DOI :
10.1109/PVSC.2013.6744374
