Design, modeling and simulation of ultra high efficient inverted metamorphic III-V multijunction solar cells

A comprehensive design, modeling and simulation of multijunction solar cells utilizing alloys of III-V semiconductor materials have been presented. Bandgap engineered subcells are examined to construct a novel multijunction solar cell comprising of AlInGaP /InGaP/InGaAs/InGaSb and a triple junction solar cell comprising of InGaP/InGaAs/InGaSb.;A wider band gap subcell AlInGaP was used as the top cell, while the bandgap of InGaP and InGaAs were tuned to capture wider range of photons. The band gaps of each subcells are strategically chosen for effective splitting of solar radiation spectrum using different %ages of the III-V semiconductor materials. The subcell layers not only capture photons in visible and ultraviolet region but are also capable of capturing photons in the near and far infrared regions.;Quantum efficiencies of each subcell layers have been optimized by varying the emitter thicknesses, base thicknesses, surface recombination velocities and lifetimes of minority charge carriers. A newer method to compute short circuit current density produced by each subcell have been introduced which was useful to generate Current density versus voltage curves. Maximum efficiency of novel solar cell designs were achieved by current matching between each subcell layers. Electrical modeling of these subcells have been performed to determine the parallel resistance and series resistance offered by each subcell layer. The proposed ultra-high efficient quadruple junction and triple junction solar cells have theoretical efficiencies of 56.8 % and 32.8 % respectively.