Influence of air exposure duration and a-Si capping layer thickness on the performance of p-BaSi{sub 2}/n-Si heterojunction solar cells

Journal Article · Mon Aug 15 00:00:00 EDT 2016 · AIP Advances

DOI:https://doi.org/10.1063/1.4961063· OSTI ID:22611417

Takabe, Ryota; Yachi, Suguru; Tsukahara, Daichi; Takeuchi, Hiroki; Toko, Kaoru; Suemasu, Takashi ^[1]; Du, Weijie ^[2]

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1. Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)
2. Key Laboratory of Optoelectronic Material and Device, College of Mathematics and Science, Shanghai Normal University, Shanghai 200234 (China)

Fabrication of p-BaSi{sub 2}(20 nm)/n-Si heterojunction solar cells was performed with different a-Si capping layer thicknesses (d{sub a-Si}) and varying air exposure durations (t{sub air}) prior to the formation of a 70-nm-thick indium-tin-oxide electrode. The conversion efficiencies (η) reached approximately 4.7% regardless of t{sub air} (varying from 12–150 h) for solar cells with d{sub a-Si} = 5 nm. In contrast, η increased from 5.3 to 6.6% with increasing t{sub air} for those with d{sub a-Si} = 2 nm, in contrast to our prediction. For this sample, the reverse saturation current density (J{sub 0}) and diode ideality factor decreased with t{sub air}, resulting in the enhancement of η. The effects of the variation of d{sub a-Si} (0.7, 2, 3, and 5 nm) upon the solar cell performance were examined while keeping t{sub air} = 150 h. The η reached a maximum of 9.0% when d{sub a-Si} was 3 nm, wherein the open-circuit voltage and fill factor also reached a maximum. The series resistance, shunt resistance, and J{sub 0} exhibited a tendency to decrease as d{sub a-Si} increased. These results demonstrate that a moderate oxidation of BaSi{sub 2} is a very effective means to enhance the η of BaSi{sub 2} solar cells.

• OSTI ID: 22611417
• Journal Information: AIP Advances, Vol. 6, Issue 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AIR
APPROXIMATIONS
BARIUM SILICATES
CONVERSION
CURRENT DENSITY
EFFICIENCY
ELECTRIC POTENTIAL
ELECTRODES
FILL FACTORS
FORECASTING
HETEROJUNCTIONS
INDIUM OXIDES
LAYERS
OXIDATION
PERFORMANCE
SATURATION
SILICON
SOLAR CELLS
THICKNESS
TIN OXIDES