Improving the quantum efficiency of the monocrystalline silicon solar cell using erbium-doped zinc sulphide nanophosphor in downshift layer

Abstract

In the present work, different concentrations of trivalent erbium doping [0%–15%] into ZnS nanophosphor was synthesized by co-precipitation method. Field emission scanning electron microscopy technique was used to determine the morphology of ZnS: Er3+ [0%–15%] nanophosphor. The morphology of the as-synthesized nanophosphor was found spherical and the size of nanophosphor was varied from 20 nm to 200 nm due to agglomeration. The UV–vis absorbance spectra depicted the absorption peaks at UV region. The fluorescence (FL) spectra were studied using 250 nm excitation wavelength. The samples were emitted in the visible region. The synthesized trivalent erbium doped and undoped ZnS nanophosphor was used as downshifting material. It was incorporated with Poly-methyl-meth-acrylate (PMMA) solution for spin coating on screen printed mono crystalline silicon solar cell to improve the short wavelength quantum efficiency. The external and internal quantum efficiency of downshift layer coated solar cells were measured and compared with the solar cell without downshift layer. The relative enhancement of current density at the solar cell with 10% erbium doped ZnS nanophosphor in downshift layer was improved by 5.09% and 6.79% of relative enhancement was observed at cell efficiency.