Enhancement of Photoelectric Performance Based on Ultrathin Wide Spectrum Solar Absorption in Cruciform Microstructure Germanium Solar Cells

In this paper, the solar absorption level of PEDOT:PSS/Ge organic and inorganic hybrid solar cells (HSCs) with different parameters of cruciform microstructure (CM) is studied, using the finite-difference time domain (FDTD) method. The light absorption in HSCs with CM is above 90% in the range of 300 nm to 1300 nm. Under the AM1.5 solar spectrum, the average absorptivity of solar energy is also at a very high level. At the same time, we use DEVICE software to calculate the electrical properties, such as the open-circuit voltage (V-oc), short-circuit current density (J(sc)), and maximum power density (P-max). The electrical simulation results show that the P-max of HSCs with CM improves to 72.16% from the planar HSCs. Besides, in order to study the mechanism of solar energy absorption in HSCs containing CM, the logarithmic plots of electric field intensity of HSCs with CM and planar HSCs, are analyzed at different wavelengths. The work shows that the CM shows an excellent light-trapping effect, which reduces the surface reflectivity of HSCs, and greatly improves the photoelectric conversion efficiency of Ge solar cells.