5.5. Surface passivation
This technique is used to reduce the recombination at both front and back surfaces which occurs due to discontinuity at various interfaces or due to dangling bond and impurities present in the solar cell. These impurities or dangling bond act as recombination centre and reduce the efficiency [64]. To reduce recombination, surface passivation is used which passivates the surface by using a dielectric surface such as Si, SiO2, Si3N4. Surface passivation can also be carried out by chemical treatment or by using a thin layer of passivizing oxide. Surface passivate can also be done by heavily doping the low doped semiconductor [65].
Surface passivation technique was successfully applied in the solar cell to enhance the efficiency [66].