Semiconductor Nanomaterial Enhance The Efficiency Of The C-Si Solar Cells And Their Photoelectric Performance

In our study, CuO nanoarray, CuS QDs and CuO NLs/CuS QDs composities were grow on thesurface of the pyramid-textured c-Si wafers. The morphology, structure, chemical composition, andthe photoelectric conversion performance of CuO nanoarray, CuS QDs and CuO NLs/CuS QDs werecharacterized by FESEM, XRD，UV-vis spectra, minority carriers’ lifetime, and J-V. The detailresults are summairzed as follows:Vairety-sized arrays of CuO nanoleaves (NLs) were fabricated on the pyramid-textured c-Si wafer.The CuO NLs/c-Si solar cells show a great increase of the optical absorption and a reduction of thereflectance in the250-1250nm wavelength range, compare to the reference one. The c-Si solar cellintegrated with CuO NLs generates the graded index of refraction between the surface of Si and air,and improves light utilization efficiency by increasing the light-trapping effect and forming theresonant optical modes, which makes the multiple scatteirng of the incident light. In addition, thedeposition of p-type CuO NLs on the surface of Si wafer can form CuO NLs/c-Si junction andgenerate a built-in potential, which is beneficial for the separation of photogenerated electrons andholes, leading to the minority carrier lifetime (xeff) increase from5.7to15.0|is. The CuO NLs/c-Sistructure both reduces optical loss and improves carrier collection, distinctly enhance c-Si solar celleiffciency. The experimental results indicate that short-circuit current, and power conversionefficiency of CuO NLs/c-Si solar cell increase by10.30%and17.90%, respectively. CuO NLs/c-Sistructure is expccted to exceed the Shockley-Queisser limit of the single junction solar cell.Variety-sized CuS NCs/QDs were fabricated on the surface of the pyramid-textured c-Si wafers,the effect of the different morphology and size to the efficiency of solar cells has been studied. TheSi wafers were firstly been pre-treated, which mean that the Si wafers were etched, this lead to thesurface is very rough and formed the Si QDs. Base on this, the compact uniform and stable CuSNCs/QDs layer were deposited on the c-Si wafers by the way of SILAR. Atfer grew the CuS NCs/QDs on the c-Si wafers, absorption range tend to broaden and increase. From the final results,CuS QDs can effectively enhance photoelectric conversion efficiency. CuS QDs generate quantumconfinement effect, then increase the energy gap and beneficial to the electron transfer between theconductive bands. CuS QDs have a high absorption coefficient, and multiple exciton effect of theCuO generate multiple electric-holes per photon, the CuO QDs can provide moren electrons than Siwafer, this result in high photoelectric conversion efficiency. In addition, we fabricated the CuONLs/CuS QDs composites on the pyramid-textured c-Si wafers, the CuO and CuS can form a type IIheterojunction, which can efficiently separate photo-generated electron-hole pairs in eachsemiconductor material and reduce their recombination. Results show CuO NLs/CuS QDs integratedwith c-Si wafers have combined the advantages of their respective single phase structure, the finaleiffciency of the Si solar increased from9.39to13.0%，relatively increased by38%.