Heat treatment of amorphous silicon p-i-n solar cells with high-pressure H2O vapor

• Published in: Journal of non-crystalline solids 2012-09, Vol.358 (17), p.2285-2288
• Main Authors: Takenezawa, J., Hasumi, M., Sameshima, T., Koida, T., Kaneko, T., Karasawa, M., Kondo, M.
• Format: Article
• Language: English
• Subjects: a-Si:H solar cell; Applied sciences; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Conversion efficiency; Cross-disciplinary physics: materials science; rheology; Electronics; Energy; Exact sciences and technology; Materials; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Natural energy; Photovoltaic conversion; Physics; Solar cell characteristics; Solar cells. Photoelectrochemical cells; Solar energy; Surface treatments
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2012.01.057

We report improvement in characteristics of hydrogenated amorphous silicon (a-Si:H ) p-i-n structured solar cells by high-pressure H2O vapor heat treatment. a-Si:H p-i-n solar cells were formed on glass substrates coated with textured SnO2 layer. P-, i-, and n-type a-Si:H layers were subsequently formed by plasma enhanced chemical vapor deposition. Finally an indium-tin-oxide layer was coated on the n-type a-Si:H surface. Heat treatment at 210°C with 2×105 Pa H2O vapor for 1h was applied to the a-Si:H p-i-n solar cells. Electrical characteristics were measured when samples were kept in dark and illuminated with light of AM 1.5 at 100mW/cm2. The heat treatment with H2O vapor increased fill factor (FF) and the conversion efficiency from 0.54 and 7.7% (initial) to 0.57 and 8.4%, respectively. Marked improvement in solar cell characteristics was also observed in the case of a poor a-Si:H p-i-n solar cell. FF and the conversion efficiency were increased from 0.29 and 3.2% (initial) to 0.56 and 7.7%, respectively. ► Application of high-pressure H2O vapor heat treatment to a-Si:H solar cells. ► Increases in FF and efficiency by treatment at 210°C at 2×105 Pa H2O for 1h. ► A conversion efficiency increased from 7.7% to 8.4%. ► Carrier recombination sites were decreased by the H2O vapor heat treatment.