Dislocation and Saturation Current Density Analysis by Rear-Side Al Amount Variation for n-Type Al-p⁺ Emitter Crystalline Silicon Solar Cell

This paper presents a dislocation and saturation of current density analysis by varying the amount of rear-side Al. The fabrication process optimizes an aluminum-alloyed emitter using a screen printing number and varying the co-firing on n-type crystalline silicon (c-Si) wafers using a suitable industry method. N-type silicon materials have high diffusion-lengths due to the reduced recombination activities of metal impurities and other nonmetallic defects compared with p-type silicon and this fulfills the requirement for innovative solar cells. To utilize the advantage of the n-type silicon wafers for manufacturing simple and industrially feasible high-efficiency solar cells, we adopted screen-printing and co-firing of aluminum (Al) alloyed n ⁺ n p ⁺ solar cells featuring a rear Al-p⁺ emitter easily fabricated through the screen-printing process. We achieved a back surface field (BSF) that was 7 μm in thickness by applying 13.14 mg/cm² of Al paste in by printing on both sides and heating the material in an high temperature infra-red (IR) furnace at a peak temperature of 756.5 °C. In the furnace, the temperature increased at a rate of 70.82 °C/sec with an efficiency of 17.36%, saturation current density J ₀₁ of 7.16 × 10^–9 mA/cm² and J ₀₂ of 3.55 × 10^–5 mA/cm², respectively.