Effective Mn dopant on optical and electrical properties of CdxMn1-xSe films for quantum dot sensitized solar cell application
Ha Thanh Tung, Dang Huu Phuc, Bui Van Thang, Hieng Kiat Jun
) were synthesized by the chemical bath deposition for the prepared photoanodes in the quantum dot sensitized solar cells. Thus, the properties of ternary films as structure, optical properties, and electrical properties were investigated more details. The structure of the CdxMn1-xSe films was characterized using the X-ray diffraction, which indicated the zinc Blende structure corresponding to all samples. The optical properties of the CdxMn1-xSe films were illustrated by the experimental absorption spectra with different doping concentrations, which combined with the Tauc correlation to estimate the absorption density, the optical band gap, the valence band and conduction band positions in the ternary compound CdxMn1-xSe, steepness parameter and electron – phonon interaction. The result shows that the values of optical parameters were very sensitive to the doping concentration as a function composition. Generally, we have optimized the optical properties at 20%-Mn dopant. Moreover, we also studied the electrical properties of the CdxMn1-xSe from photocurrent density curves, which connected with the one J-V method to determine the Rs, RSH dynamic resistances. The recombination resistances, diffusion resistances in TiO2 layer, and TiO2/QDs and counter electrode/polysulfide electrolyte contacts, Rct1, Rct2, were estimated from the fitting of electrochemical impedance spectrum. These results are important to explain the obtained performance efficiency from the J-V curves.
Absorption, Band gap, Solid state, Materials, Optical properties