Increase in efficiency and material yield by use of PECVD silicon nitride in a simple screen printing process on Solarex material [solar cells]

This work presents a simple screen printing solar cell process based on firing the front contacts through a silicon nitride (SiN_x ) layer deposited by direct plasma enhanced chemical vapour deposition (PECVD). This processing sequence of only six steps results in an excellent front surface and bulk passivation. Efficiency improvements up to 1.5% compared to a state-of-the art processing sequence were obtained on Solarex multicrystalline material. Independently confirmed efficiencies of almost 16% were reached. First indications of the excellent passivation quality of SiN_x deposited by direct PECVD on p-Si are given