Lead-free glass powder used for back passivation point contact solar cell aluminium paste, and preparation method thereof

Abstract

The invention discloses lead-free glass powder used for a back passivation point contact solar cell aluminium paste, and a preparation method thereof. The lead-free glass powder is prepared from the following ingredients in parts by weight: 20-50% of ZnO, 5-25% of V2O5, 13-30% of B2O3, 10-25% of Al2O3, 1-5% of SiO2, 1-5% of CaO, 1-10% of Bi2Se3 and 1-10% of MoTe2. All components are mixed after being stirred and rotated for 1 h in a blender mixer; mixed materials are smelted in a resistance furnace at the temperature of 1110-1250 DEG C, and nitrogen is introduced to keep the temperature for 30-60 min; molten fused glass is rolled into a thin sheet; the thin sheet is smashed to granularity for 1-3 mum, and then, glass powder is subjected to airflow grading sieving to obtain the lead-free glass powder of which the median particle diameter is 1.5-2.5 mu m and the softening temperature is 480-510 DEG C. The lead-free glass powder does not contain lead oxide and has a low softening point, an aluminium electrode and a silicon substrate form good ohmic contact, and the conversion efficiency of the prepared solar cell is high.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a lead-free glass powder for back passivation point contact solar cell aluminum paste, and also relates to a preparation method of the back passivation point contact solar cell aluminum paste. Background technique [0002] The efficiency of ordinary crystalline silicon solar cells is usually lower than 20%. At present, in order to improve the conversion efficiency of solar cells and reduce the cost of crystalline silicon, rear passivated point contact solar cells (Passivated Emitter and Rear Cell, referred to as PERC) because their efficiency is higher than 20%, gradually becoming a hot spot in solar cell research. Different from ordinary crystalline silicon solar cells, the key to PERC cells is back passivation and point contact, that is, a passivation film is coated on the back of the cell silicon wafer, the back electrode adopts the form of point contac...

AI Technical Summary

Problems solved by technology

In order to pursue a low softening point, these glass powders usually contain Pb elements that are harmful to the environment. This element is not good for the environment and will cause great harm to the human body.

[0004] Chinese patent CN107673623A discloses a glass frit for double-sided PERC aluminum paste and its preparation method. In the high-lead glass frit, the spiral network structure formed by lead oxide and silicon dioxide enables the glass frit to destroy the aluminum film and silicon Substrate, promotes the formation of aluminum-silicon alloy and the compactness of the aluminum layer, and has good electrical conductivity, but the glass powder component still contains up to 20-50% lead oxide, which is not suitable for environmental protection requirements