Selectively electroless deposited Ag nanoparticles embedded in the dielectric layer to tune the rear color of bifacial solar cells

In this paper, a simple method to grow silver nanoparticles (Ag-NPs) onto a thin dielectric layer on silicon substrates is presented by using a wet-based chemical technique. The mechanism of Ag-NPs in-situ growth on dielectric films, and the influence of the dielectric materials, the thickness of dielectric film and the reaction time on the morphologies of Ag-NPs were investigated. Moreover, the Ag-NPs have been integrated into the rear dielectric layers (Al2O3/SiNx) of bifacial monocrystalline silicon passivated-emitter–rear-contact (mono-Si PERC) solar cells. The cells show not only the acceptable electrical performance, i.e. the average efficiency gain ~0.04% and the highest efficiency of 22.71%, but also the tunable rear colors. The research in this paper provides a feasible approach for tunning the rear color of the solar cells, which has potential to be applied in building integrated photovoltaics (BIPV) in terms of aesthetical aspects. We proposed a simple method to grow silver nanoparticles (Ag-NPs) onto a thin dielectric layer on silicon substrates by using a wet-based chemical technique. Moreover, the Ag-NPs have been integrated into the rear dielectric layers (Al2O3/SiNx) of bifacial monocrystalline silicon passivated-emitter–rear-contact (mono-Si PERC) solar cells, showing the acceptable electrical performances with an averaged efficiency increased by 0.04% and the highest efficiency of 22.71%, and showing fascinating rear colors. [Display omitted] •A simple method to grow Ag-NPs onto a dielectric layer on Si substrates is presented by using a wet chemical technique.•The growth of Ag-NPs on SiNx and Al2O3 is selective in this method.•The introduction of Ag-NPs improves the cell performances, and the rear color of the bifacial cells can also be adjusted.•This deposition method of Ag-NPs has the potential to be integrated into the industrial bifacial Si cell process sequence.