Charge Transfer and Separation Mechanism in Dye–Sensitized Nano solar Cells

Abstract

Six samples of solar cells were fabrication in this research study by deposited poly (2-methoxy-5-(2’-ethyl-hexyloxy)-1.4 phenylene) (MEH-PPV) polymer layer on the indium tin oxide (ITO) glass, and deposited another layer of dye(Sodium4[2(1hydroxynaphthalen2yl)hydrazin1ylidene]7noxonaphthalene1s ulfonate(EcrchromBlackT),dibenzothiatricarbocyanineIodideHexadibenzocyaini 45 C33H29N2S2I (DDTTC), tow samples mead by deposited zinc oxide (ZnO), cupric oxide (CuO)layers. Aluminum (Al) electrode was used to complete the formation of solar cells. The solar cells were exposed to light and the current and voltages were recorded to calculate their efficiency. The samples were characterized by Ultra violet-visible spectroscopy to display absorption spectrum. The rapid increase of the absorption in the low wavelength and decrease in special wavelength, referring to electronic transition, and this decrease is continuous with the decrease of photon energy. The range of absorption beak wavelengths for CuO +ZnO was obtained at330 nm, for MEH-PPV + DDTTC obtained at (300 nm and 500 nm) respectively.For the purpose of the present study Electronic transport in the (Six samples of solar cells ) devices is studied via current density voltage (J-V) curves, taken using a Keithley 2400 source meter by sourcing voltage across the ITO (positive) and aluminum Al (negative)electrode .the open circuit voltage Voc is the applied voltage at which the current density is zero under illumination is determined by the difference between the quasi-Fermi energy level of the (DDTTC = 2.2 eV ‘ Eriochrome black T = 2.16 eV ‘ Cu O = 2.9 eV and ZnO = 3.6 eV )and the work function of the Al electrode (4.08 eV)or the highest occupied molecular orbital (HOMO) level of the MEH-PPV in our system.