Performance enhancement of ZnSnP2 solar cells by a Cu3P back buffer layer

In this study, we investigated reactive diffusion at the interface between a Cu back electrode and ZnSnP2 absorber, which ohmic behavior was previously confirmed by appropriate annealing. Cross-sectional observation of Cu/ZnSnP2 revealed that Cu3P formed along surface after It also found epitaxially beside with lattice-mismatch less than 0.5% electron diffraction around Cu3P/ZnSnP2 consideration atomic arrangements, particularly phosphorus sublattice, in both phosphides. addition, photoelectron yield spectroscopy work function ionization potential are about 5.2 eV, suggesting barrier against hole transport is small interface. The formation leads to higher current density no roll-over J-V curves solar cells. Consequently, highest efficiency cells 3.87% achieved intentionally prepared using sputtering. concluded promising buffer material for due alignment from viewpoints band lattice structures.