Investigation of Atomic Layer Deposition Al2O3 Passivation for Screen-Printed Large-Area Solar Cells

• Published in: IEEE journal of photovoltaics Vol. 6; no. 4; pp. 869 - 874
• Main Authors: Kang, Moon Hee, Ok, Young-Woo, Rohatgi, Ajeet
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.07.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Al2O3; Aluminum oxide; Atomic layer deposition; atomic layer deposition (ALD); Passivation; Photovoltaic cells; Si solar cell; Silicon; Surface morphology; atomic layer deposition (ALD); passivation; Si solar cell; Al2O3
• ISSN: 2156-3381; 2156-3403
• DOI: 10.1109/JPHOTOV.2016.2556982

Thermal and plasma-assisted atomic layer deposition (ALD) <inline-formula><tex-math notation="LaTeX"> {\mathrm{A}}{{\mathrm{l}}_2}{{\mathrm{O}}_3}</tex-math></inline-formula> films for surface passivation of Si solar cells are investigated. ALD <inline-formula><tex-math notation="LaTeX">{\mathrm{A}}{{\mathrm{l}}_2}{{\mathrm{O}}_3} </tex-math></inline-formula> films were deposited on both Czochralski (Cz) and float-zone wafers with textured and planar surface, and then, surface recombination velocity (SRV) was measured. An extremely low SRV of 3 cm/s after annealing and 13 cm/s after contact firing was achieved from plasma-assisted ALD <inline-formula> <tex-math notation="LaTeX">{\mathrm{A}}{{\mathrm{l}}_2}{{\mathrm{O}}_3}</tex-math></inline-formula> on a 2-Ω⋅cm Cz wafer. In addition, screen-printed large-area (239-cm 2 ) textured solar cells were fabricated using plasma-assisted ALD <inline-formula><tex-math notation="LaTeX"> {\mathrm{A}}{{\mathrm{l}}_2}{{\mathrm{O}}_3}</tex-math></inline-formula> films and compared with <inline-formula> <tex-math notation="LaTeX">{\mathrm{Si}}{{\mathrm{O}}_{\rm{2}}}</tex-math></inline-formula>-passivated solar cells. Superior conversion efficiency of 20.0% (n-type) and 18.6% (p-type) was achieved from ALD <inline-formula><tex-math notation="LaTeX">{\mathrm{A}}{{\mathrm{l}}_2}{{\mathrm{O}}_3}</tex-math></inline-formula> passivation, while <inline-formula><tex-math notation="LaTeX">{\mathrm{Si}}{{\mathrm{O}}_{\rm{2}}}</tex-math> </inline-formula>-passivated solar cells provide 19.8% (n-type) and 17.7% (p-type).