Influence of doping profile of highly doped regions for selective emitter solar cells
The influence of the doping profile under the metallization for laser doped selective emitter solar cells is investigated. Laser doping allows profile tailoring to some extent by adapting the pulse energy, resulting in Gaussian doping profiles. Numerical calculations using PC1D show that the doping profile influences the recombination at the metal-semiconductor interface. The value J0e,met is used to characterize this influence on solar cell level employing calculations with the 2-diode-model. Selective emitter solar cells have been fabricated to validate, whether this effect can be observed on cell level. IV measurements show a dependence of the open circuit voltage on the profile. This is determined to be partly due to a different 2nd diode recombination current J02 for different doping profiles underneath the contact. The effect of J0e,met is also ascertainable.