Modelling and comparison of light trapping caused by textured interfaces and nanoparticles in thin film solar cells

The efficiency of thin film solar cells can be improved by various known and extensively studied light trapping techniques such as textured interfaces, nano-particles, and so on. But all these methods are not expected to improve the efficiency of the solar cells with by same amount. In this paper, textured interfaces and nano-particles are simulated and their respective effect on the absorption of the active layer, aSi : H in this case, is observed. The nano-particles are silver nano-particles and for the interface simulations, different AFM scans are used. For the nano-particles simulations different position in the layer stack is simulated. To achieve this, Maxwell's equations are solved with Finite Difference Method(FDM) and Finite Integration Technique(FIT) and special scheme that accounts for the negative permittivity of silver. To accurately simulate the silver nano-particles the simulation is done with a fine discretization and run on high performance machines with a highly parallel iterative scheme.