Aluminium paste used for back passivated crystalline silicon solar cell, and preparation method thereof

The invention discloses an aluminium paste used for a back passivated crystalline silicon solar cell, and a preparation method of the aluminium paste. The aluminium paste comprises the following components in percentage by mass: 75-77 wt% of aluminum powder, 5-10% of aluminum silicon alloy powder, 21-28 wt% of an organic carrier, 1-5 wt% of glass powder, and 0-3 wt% of an additive and an assistant. The preparation method of the aluminium paste disclosed by the invention comprises the steps of: preparing the glass powder, preparing the organic carrier and processing the paste. The invention aims at the special aluminium paste applied to the back passivated crystalline silicon solar cell in which holes or grooves are formed in the back surface by means of laser so as to form local aluminium-silicon ohmic contact. The aluminium paste has the advantages of excellent flowability and wettability, small capability of eroding a passivation film layer, high filling rate at laser film opening positions, compact sintere