Improvement of multicrystalline silicon wafer solar cells by post-fabrication wet-chemical etching in phosphoric acid

• Published in: Bulletin of materials science Vol. 34; no. 7; pp. 1689 - 1692
• Main Authors: Mefoued, A., Fathi, M., Bhatt, J., Messaoud, A., Palahouane, B., Benrekaa, N.
• Format: Journal Article
• Language: English
• Published: India Springer-Verlag 01.12.2011; Springer Nature B.V
• Subjects: Ammonia; Antireflection coatings; Chemical etching; Chemical treatment; Chemistry and Materials Science; Electric contacts; Engineering; Materials Science; Phosphoric acid; Photovoltaic cells; Plasma enhanced chemical vapor deposition; Silicon nitride; Silicon substrates; Silicon wafers; Solar cells; Surface treatment; AFM; H; passivation; Silicon; PECVD; etch; PO
• ISSN: 0250-4707; 0973-7669
• DOI: 10.1007/s12034-011-0378-8

In this study, we have improved electrical characteristics such as the efficiency ( η ) and the fill factor (FF) of finished multicrystalline silicon ( mc -Si) solar cells by using a new chemical treatment with a hot phosphoric (H 3 PO 4 ) acidic solution. These mc -Si solar cells were made by a standard industrial process with screen-printed contacts and a silicon nitride (SiN) antireflection coating. We have deposited SiN thin layer (80 nm) on p -type mc -Si substrate by the mean of plasma enhanced chemical vapour deposition (PECVD) technique. The reactive gases used as precursors inside PECVD chamber are a mixture of silane (SiH 4 ) and ammonia (NH 3 ) at a temperature of 380°C. The developed H 3 PO 4 chemical surface treatment has improved η from 5·4 to 7·7% and FF from 50·4 to 70·8%, this means a relative increase of up to 40% from the initial values of η and FF. In order to explain these improvements, physical (AFM, EDX), chemical (FTIR) and optical (spectrophotometer) analyses were done.