For the description of charge transport at hetero-interfaces, which would be suppressed in the drift-diffusion picture, a hopping model in the spirit of the Miller-Abrahams theory of thermally activated tunneling is used. The electronic model takes into account the peculiar properties of organic semiconductors in terms of different mobility models reflecting the presence of disorder and localization. For the simulation of charge carrier and exciton transport, the drift-diffusion module is used, with generation rates inferred from the optical simulation. The coupling is performed via extraction of transmission and reflection coefficients from the transfer matrix and ray-tracing models to be used in the net-radiation formalism.
The multiscale optics approach where a transfer matrix formalism for the optics of coherent layer stacks and a 3D ray-tracing simulation of scattering at large scale textures are coupled to a net-radiation model for incoherent light propagation is shown in Fig. For this purpose we make combined use of several modules of Setfos: Optical generation of charge carriers due to light absorption in the active layers is simulated using the absorption module, which in the case of textured interfaces is coupled to the advanced optics module. The (optical) optimization of fully textured perovskite-silicon tandems, on the other hand, is made possible by combining the models for the light scattering at silicon textures and for the wave propagation in thin-film silicon and perovskite layers into a dedicated multi-scale simulation framework.įor the simulation of complex tandem solar cell devices, the modeling of transport of charge carriers and excitons needs to be joined with a multi-scale framework for the optical simulation of quasi-1D architectures. Electrical stimulation of all-organic tandems is enabled by a novel hopping transport model for the description of charge transfer across organic-organic interfaces. We address the above challenges using an integrated optoelectronic device simulation framework designed for the numerical optimization of organic solar cell and light-emitting devices.
In the case of the perovskite-silicon tandem, the widespread use of silicon hetero-junction technologies featuring combinations of large-scale textures with thin-film contact layers, but also the peculiarities of the perovskite materials in terms of the effects of ion-migration pose challenges to both optical and electrical simulation of such multijunction devices.
#QUANTUMWISE HETERO LAYER DEVICE FULL#
In organic tandems, while the optical simulation of the thin-film layer stacks is routinely used, full optoelectronic device simulation including the recombination junction formed by the interlayer region is not common. Numerical device simulation can provide instrumental insight for the identification of the optimum multilayer configuration.
#QUANTUMWISE HETERO LAYER DEVICE SERIES#
Designing multijunction solar cells requires optimization of a large number of structural and compositional parameters, such as band gaps and layer thicknesses of the component materials, but also the interlayer design for the series connection in the case of the industrially more relevant monolithic tandem devices.