A highly efficient (>6%) Cd1−xMnxSe quantum dot sensitized solar cell

Abstract

Quantum dot sensitized solar cells (QDSCs) have attracted considerable attention recently and become promising candidates for realizing a cost-effective solar cell. The design and synthesis of quantum dots (QDs) for achieving high photoelectric performance is an urgent need imposed on scientists. Here, we have succeeded in designing a QDSC with a high efficiency η of 6.33% based on Cd_0.8Mn_0.2Se quantum dots by facile chemical bath deposition (CBD). The effects of Mn²⁺ ions on the physical, chemical, and photovoltaic properties of the QDSCs are investigated. The Mn²⁺ ions doped into QDs can increase the light harvesting to produce more excitons. In addition, the Mn²⁺ dopant also raises the conduction band of CdSe, accelerates the electron injection kinetics and reduces the charge recombination, improving the charge transfer and collection. The increase of the efficiencies of light-harvesting, charge-transfer and charge-collection results in the improvement of the quantum efficiency of the solar cells. The power conversion efficiency of the solar cell is increased to 6.33% (V_oc = 0.58 V, J_sc = 19.15 mA cm⁻², and FF = 0.57).