Optical properties and dynamic process in metal ions doped on CdSe quantum dots sensitized solar cells

Ha Thanh Tung; Dang Huu Phuc

doi:10.3788/COL201816.072501

Abstract

In recent years, the nanostructure for solar cells have attracted considerable attention from scientists as a result of a promising candidate for low cost devices. In this work, quantum dots sensitized solar cells with effective performance based on a co-sensitized

CdS / CdSe : {Mn}^{2 +}

(or

{Cu}^{2 +}

) nanocrystal, which was made by successive ionic layer absorption and reaction, are discussed. The optical, physical, chemical, and photovoltaic properties of quantum dots sensitized solar cells were sensitized to

{Mn}^{2 +}

and

{Cu}^{2 +}

dopants. Therefore, the short current (

J_{SC}

) of the quantum dot sensitized solar cells is boosted dramatically from

12.351 mA / {cm}^{2}

for pure CdSe nanoparticles to

18.990 mA / {cm}^{2}

for

{Mn}^{2 +}

ions and

19.915 mA / {cm}^{2}

for

{Cu}^{2 +}

ions. Actually, metal dopant extended the band gap of pure CdSe nanoparticles, reduced recombination, enhanced the efficiency of devices, and improved the charge transfer and collection. In addition,

{Mn}^{2 +}

and

{Cu}^{2 +}

dopants rose to the level of the conduction band of pure CdSe nanoparticles, which leads to the reduction of the charge recombination, enhances the light-harvesting efficiency, and improves the charge diffusion and collection. The results also were confirmed by the obtained experimental data of photoluminescence decay and electrochemical impedance spectroscopy.

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