Plasma-enhanced chemical vapor-deposited SiN and liquid-phase-deposited SiO2 stack double-layer anti-reflection films for multi-crystalline solar cells

We successfully fabricated a double-layer anti-reflection film for multi-crystalline silicon solar cells through liquid-phase deposition to deposit silicon dioxide (SiO2) film on a multi-crystalline silicon surface and plasma-enhanced chemical vapor deposition to deposit silicon nitride (SiN) film on a SiO2 film surface. The SiO2 film thicknesses were 10, 15, and 20 nm, and the SiN film thickness was 60 nm. The reflectance of the substrate markedly decreased as the double-layer film was deposited. Moreover, with different film thicknesses, the minimal values of the reflectance were 4.91%, 2.75%, and 2.83% at the wavelengths of 609, 597, and 634 nm. The average reflection reached 6.92% when the thicknesses of SiO2 and SiN films were 20 and 60 nm in the wavelength range of 400-1100 nm. The minority carrier lifetimes of the multi-crystalline silicon substrates were 7.44, 7.21, and 7.27 μs at different film thicknesses. The short circuit current density and efficiency of the solar cell reached 34.52 mA/cm2 and 16.56% when the thicknesses of the SiO2 and SiN films were 20 and 60 nm, respectively. Low reflectance and good cell performance indicated that the double-layer film composed of SiO2 and SiN films were suitable for multi-crystalline silicon solar cells as the anti-reflection film.