Influence of ultrathin gahnite anti-reflection coating on the power conversion efficiency of polycrystalline silicon solar cell

Abstract

Current research has concentrated on the development of ZnAl2O4 (gahnite) spinel nanostructure through anti-reflection coating (ARC) material for improved power conversion efficiency (PCE) of polycrystalline silicon solar cells. Radio frequency magnetron sputtering technique was adopted to deposit transparent polycrystalline gahnite nano-microfilms at room temperature. Material deposition was performed in a pure argon atmosphere on polycrystalline silicon solar cell substrates with a coating duration of 5–45 min. The influence of gahnite spinel nanostructure-integrated coating on the efficiency of silicon solar cell was explored by investigating physical, electrical, optical characteristics and temperature distribution profiles. The synthesized ARC material has gahnite spinel crystal structure composed of two-dimensional (2D) nanosheets. Atomic force microscopy study revealed that the thickness of synthesized gahnite 2D nanosheets was about 50 nm. The resistivity of gahnite coated with the time duration of 35 (T-IV) minutes on silicon solar cell was measured to be 1.93 × 10−3 Ω cm. The nano-microfilms showed a great optical transmittance (97%) in the wavelength range of 300–800 nm. The maximum PCE of 21.27% at open atmospheric condition and 23.83% at controlled atmospheric condition had been achieved for 35 (T-IV) minutes of gahnite nano-microfilm coating and it has been proved that gahnite nano-microfilms assists the absorption of more photons on a polycrystalline silicon solar cell substrate. The results acquired indicate that the gahnite nano-microfilm is an appropriate ARC material for polycrystalline silicon solar cells to enhance the PCE.