Studies On The Preparation And Properties Of CdS/ZnO Antireflection Coatings For C-si Solar Cells

In this paper, ZnO nanorod arrays antirelfection (ZnO NRAs) coatings and CdS/ZnO NRAscoatings were synthesized on the surface of c-Si solar cells through the chemical bath method (CBD).The structure, morphology and optical properties of the coatings were characteirzed usingfluorescence spectroscopy (PL), UV-visible-near-infrared (UV-Vis-NIR) reflection absorptionspectroscopy, transmission electron microscopy (TEM), high resolution transmission electronmicroscopy (HRTEM), field emission scanning electron microscope (FESEM) and X-ray diffraction(XRD). The photoelectrical properties of cell with antireflection coatings were tested using sun lightsource simulator and electrochemical workstation.ZnO NRAs antireflection coating with diameter of40-100nm and length of370-1000nm wereprepared using CBD, and the bath temperature was90"C. The effects of different deposition timefrom lOmin to60min on the coatings’ morphology were studied. For the simple with deposition timeof30min，the coating can significantly enhance the light-captuirng capability of crystal silicon cells,further increasing the carrier concentration and the photocurrent. When the depositon time wasextended to lh，since the cell was immersed in the solution for a long time, the cell was corroded byof the reaction solution and resulting the downshitf of the cell performances. PL spectra of ZnOnanorods showed a significant near band-edge-ultraviolet emission and green-yellow light emission.CdS/ZnO NRAs antireflection coatings were also made through the CBD method. CdSnanoparticles with diameter of60-7Onm are on the top layer of ZnO nanorods, and the total thicknessof the composite coating is about450nm. The defect emission of ZnO nanorods can be suppressedby the light scattering effect of the CdS particles.The as prepared coatings can take advantage ofhight energy wave ranger of the solar energy spectrum and improving the photoelectric conversion efficiency. Under AM1.5G simulator radiation condition, CdS/ZnO NRAs coating can improve thephotoelectric conversion efficiency of crystalline silicon cells, and the efficiency value was close tocommercial SiNx anti-reflection film solar cells.