Studying the impact of Mg doping on the physical properties of CdS nanocrystals for the fabrication of hybrid solar cells–based organic P3HT : PCBM polymers and inorganic Mg‐doped CdS nanocrystals

Abstract

Herein, the influence of Mg-doped CdS nanocrystals (NCs) on the performance of hybrid solar cells (HSCs) is investigated for the first time. Pristine and Mg-doped CdS NCs at different concentrations (0.25, 0.5, and 0.75 mol%) are synthesized using the heating up method. The effect of Mg on structural, compositional, morphological, optical, and electrical properties of CdS NCs is examined. The structural analysis showed a peak shift toward a higher wavelength, while lattice parameters a and c are decreased. As the Mg concentration increases, the shape and size of the CdS NCs are considerably changed, while the bandgap is tuned from 2.66 to 2.44 eV. Besides, the resistivity of CdS is significantly decreased while carrier concentration increases. Then, the device is fabricated with a configuration of FTO/TiO2/P3HT:PC61BM/MoO3/Ag, wherein the influence of different concentrations of undoped and Mg-doped CdS NCs on the performance of HSCs is explored. The Mg-doped CdS NCs exhibited a power conversion efficiency of 2.92%, 2.5 times higher than the polymer device. Thus, the results revealed that the Mg doping significantly improved the properties of CdS NCs and the performance of HSCs. Henceforth, this work would provide a new path to enhance the power conversion efficiency of the HSCs in a low-cost approach.