Magnetoresistance and Carrier Collection in Bifacial Multicrystalline-Si Solar Cells: Role of Base Thickness and Illumination Mode
Moussa Toure1, Mamadou Lamine Samb2, Youssou Gning3, Aly Toure4, Ahmed Mohamed-Yahya5
1Moussa TOURE, Professor, Department of Physics and Chemistry, University Iba Der Thiam of Thies, Thies, Senegal.
2Mamadou Lamine Samb, Associate Professor, Department of Physics and Chemistry, University of Iba Der Thiam of Thies, Thies, Senegal.
3Dr. Youssou N Ging, Professor, Department of Physics and Chemistry, University Iba Der Thiam of Thies, Thies, Senegal.
4Aly Toure, Student, Department of Physique Chimie, University Iba Der Thiam of Thies, Thies, Senegal.
5Ahmed Mohamed-Yahya, Associate Professor, Department of Physics, Université de Nouakchott Al Aasriya, Nouakchott, Mauritania.
Manuscript received on 28 August 2025 | Revised Manuscript received on 06 September 2025 | Manuscript Accepted on 15 September 2025 | Manuscript published on 30 September 2025 | PP: 26-36 | Volume-14 Issue-10, September 2025 | Retrieval Number: 100.1/ijitee.J1142140100925 | DOI: 10.35940/ijitee.J1142.14100925
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: We investigate how weak transverse magnetic fields (B = 10⁻⁴ to 10⁻³ T) influence bifacial multicrystalline-silicon photovoltaic cells operated near open-circuit conditions, focusing on the photovoltage (Vph), photocurrent density (Jph), and the apparent series resistance (Rs) as functions of base thickness (e = 100–400 μm) and illumination mode (front, rear, dual). Jph–Vph characteristics reveal a systematic increase of Rs with B, whose magnitude depends strongly on e and illumination: the effect is maximal under rear illumination, mitigated under dual illumination, and moderate under front illumination. Under rear illumination, increasing e markedly reduces carrier collection; for illustration, Jph and Vph drop from ≈10 mA·cm⁻² and 0.34 V to ≈0 mA·cm⁻² and 0.23 V when e increases from 100 to 400 μm. To quantify this behavior, we analyze Rs(e, B) and the absolute change ΔRs (maximized over the tested field window). Because the carrier-collection velocity (CCV) can vary with operating conditions, we report extractions in which CCV is either freely fitted or held fixed at 60.256 cm·s⁻¹ to isolate the magnetic contribution to Rs. The interpretation follows a magnetoresistive framework: the Lorentz force reduces the effective mobility μ(B) and, via the Einstein relation, the diffusion coefficient D(B). In the Drude limit for B ⟂ J, the longitudinal diffusion follows D∗ (B)=D/[1+(μB)²], implying a shortened diffusion length and reduced conductance. At millitesla fields, however, the intrinsic reduction of D is slight; the dominant contributions to the “apparent” Rs arise from surfaces and contacts (passivation quality, metallization), current-spreading in the base, extraction geometry (sheet vs. bulk paths), and injection level. A joint parametric extraction of {J0, n, Rs , Rsh} by illumination mode and thickness is essential to explain high-voltage slopes and to link transport parameters to performance. These findings identify practical levers, thickness selection, improved surface passivation, optimized contact design, and illumination strategy, to mitigate magnetically induced increases in Rs. They also motivate future work on field orientation, temperature dependence, and spatial mapping of Rs to localize resistive bottlenecks and guide device engineering.
Keywords: Magnetoresistance; Bifacial Solar Cells; Multicrystalline Silicon; Carrier Collection; Series Resistance; Base Thickness.
Scope of the Article: Energy Harvesting