Heterojunction solar cell electric injection process

The invention discloses an electric injection process for a heterojunction solar cell. The process comprises the following steps of: stacking a certain number of heterojunction solar cell pieces in a manner that the P surfaces of the heterojunction solar cell pieces are uniformly oriented in series; heating the solar cell to an electric injection annealing temperature, and keeping the temperature until electric injection is finished; a constant current source is applied to the two ends of the battery or the battery pack stacked in series, the current flows in from the P-type end of a PN junction of the battery and flows out from the N-type end, compressed air is started to cool the battery, and the temperature is kept constant in the current injection period; and constant current source injection is maintained for a certain period of time. According to the invention, the quasi Fermi level of electrons is changed in a manner of electrically injecting carriers into the finished battery, so that the passivation