Investigation of silver doped CdS co-sensitized TiO2/CISe/Ag–CdS heterostructure for improved optoelectronic properties

Quantum dots have attracted extreme attention due to their excellent optical performance. This study insight optoelectronic performance of the Ag doped CdS passivated CuInSe2 quantum sensitized solar cell. CuInSe2 quantum dots (CISe QDs) of 6 nm were synthesized by simple thermolysis method, followed by 3-merceptopropinic acid (MPA) ligand exchange process. Additionally, titanium dioxide nanoflowers (TiO2 NFs) were prepared by hydrothermal method. In-situ Chemical bath deposition (CBD) technique was adopted for CISe QDs sensitization, followed by co-sensitization of Ag doped CdS (Ag–CdS) layer through successive ionic layer adsorption and reaction (SILAR) method. Co-sensitization of Ag–CdS layer remarkably elevates the absorption spectra, which increase carrier generation in the quantum dots sensitized solar cells (QDSSCs). High charge transfer rate and plasmonic effect of Ag incorporated CdS nanoparticles result in the suppression of electron-hole recombination, which is confirmed by the high open circuit voltage (Voc) 640 mV of CISe/Ag–CdS compare to 510 mV of CISe solar cell. The fabricated CISe/Ag–CdS novel structure device show significantly improved optoelectronics properties, with highest power conversion efficiency (PCE) 3.34% of CISe/Ag–CdS co-sensitized solar cells.