Numerical investigation of GaAs nipi solar cell performance

Numerical investigations of GaAs nipi (n-type/intrinsic/p-type/intrinsic) doping superlattice solar cell performances have been performed and the results are presented. Models of various n-i-p-i layers were developed to explore the performance of the GaAs nipi architecture using CFDRC´s NanoTCAD 3D device simulator. Performance parameters such as I-V characteristics, quantum efficiency and power efficiency were analyzed. AM0 spectrum was assumed. Results show that the short-circuit current density and cell efficiency increase asymptotically as the number of n-i-p-i layers increase, which is traded off by an observed decrease in the open circuit voltage. For layer thicknesses of 40nm, the optimum superlattice doping is on the order of 1E18 cm^-3. The 10 layer nipi structure demonstrates a potential of dramatic relative efficiency increase (62%) compared to a single layer nipi device.