The proper design of the multi-junction solar cell (MJSC) requires the optimisation
search through the vast parameter space, with parameters for the
proper operation quite often being constrained, like the current matching
throughout the cell. Due to high complexity number of MJSC device parameters
might be huge, which makes it a demanding task for the most of
the optimising strategies based on gradient algorithm. One way to overcome
those difficulties is to employ the global optimisation algorithms based on
the stochastic search. We present the procedure for the design of MJSC
based on the heuristic method, the genetic algorithm, taking into account
physical parameters of the solar cell as well as various relevant radiative and
non-radiative losses. In the presented model, the number of optimising parameters
is 5M + 1 for a series constrained M-junctions solar cell. Diffusion
dark current, radiative and Auger recombinations are taken into account
with actual ASTM G173-03 Global tilted solar spectra, while the absorption
properties of individual SCs were calculated using the multi band k · p
Hamiltonian. We predicted the efficiencies in case of M = 4 to be 50:8%
and 55:2% when all losses are taken into account and with only radiative
recombination, respectively.
Keywords: Multi Junction Solar Cells, Current Matching, III-V
semiconductors, Auger effect, Genetic Algorith
