Multiscale Optical Modeling of Perovskite-Si Tandem Solar Cells

With the success of silicon (Si) solar cell technology, research and development on higher efficiency multijunction cells is gaining much attention. Tandem with a perovskite top Si bottom show particular potential. However, optical modeling such devices complicated by broad range length scales involved; optically thin layers nanoscale features require some version wave optics or even full field electromagnetic (EM) calculations, while micrometer scale structuring large dimensions are more manageable using geometrical (ray) optics. In present work, method for combining EM ray calculations developed described in detail, examples provided software Comsol Multiphysics. For regions films features, performed finite element method. These provide phase amplitude waves diffracted into different orders, which only regular reflection transmission typically relevance periodicity. simulation, corresponding implemented as diffracting interfaces, deterministic transformations Stokes vector components according to calculations. Meanwhile, absorbed intensity intersecting rays recorded. The applied separate few tandem two- versus four-terminal configurations. Corrections strongly absorbing media tracing algorithm, use generalized versions Fresnel coefficients, Snell’s law Beer-Lambert law, also evaluated. typical front surface structure inverted pyramids, corrections found reduce absorption up 0.5 percentage units compared conventional calculation. difference concluded originate mainly from reduced rates inhomogeneous waves, rather than enhanced escape probabilities (quasi-) trapped at surface. further evaluate effects plasmonic nanoparticle array, embedded stack that located directly microstructured