A High Efficiency Si-Ge Based Novel Multijunction Solar Cell

Abstract

This research is focused on a new type of three junction high efficiency solar cell incorporating the promising Si-Ge material as the bottom layer. As a proof of concept, the proposed solar cell has been configured with high quality material of bandgaps 1.9 eV GaInP 2 and 1.42 eV GaAs as top and middle subcells and 0.838 eV bandgap Si 0.38 Ge 0.62 new semiconductor material as bottom subcell. The chosen materials for this configuration are lattice matched (5.66 Å) and this matching is beneficial for optical transparency and current conductivity. The short circuit current density (J sc ), reverse saturation current density (J 0 ), open circuit voltage (V oc ), voltage (V m ) and current density (J m ) at maximum power point, fill factor (FF) and the photoconversion efficiency (η) for the proposed multijunction solar cell (MJSC) have been determined by using the standard solar cell equations of modified spectral p-n junction model and MATLAB in-house code. The ASTM G173-03 reference spectra have been utilized for the quantitative analysis at airmass AM1.5G global irradiance condition. The conversion efficiency of the GaInP 2 /GaAs/Si 0.38 Ge 0.62 solar cell has been simulated as 47.1% at AM1.5G under normal sun (1 sun) concentration and 56.4% under 1000 suns concentration.

Maximizing Conversion Efficiency: A Numerical Analysis on P+ a-SiC/i Interface/n-Si Heterojunction Solar Cells with AMPS-1D

“…In paper [28], the efficiency of the Si-based heterojunction solar cell was improved from 3.39% to 3.98% using the coupled ZnO-SnO 2 nanocomposite. The efficiency of the Si-Ge-based multijunction solar cell is simulated to be 47.1% under normal sun conditions and 56.4% under 1000 sun concentrations achieved in [29]. In the study [30], for 100 m and 50 m thick Rib-Si solar cells, respectively, the Si-based heterojunction solar cell obtained conversion efficiencies of 20.2 percent and 19.9 percent.…”