Assemble of porous heterostructure thin film through CuS passivation for efficient electron transport in dye-sensitized solar cells

Three different modified solar cells have been passivated with copper sulfide (CuS) on a TiO₂ electrode and manganese sulfide (γ-MnS) hexagonal as photon absorbers. The MnS were prepared using (a-c) bis(N-Piperl-N-p-anisildithiocarbamato)Manganese(II) Complexes Mn[N-Piper-N-p-Anisdtc] as (MnS_1), N-p-anisidinyldithiocarbamato Mn[N-p-anisdtc] as (MnS_2) and N-piperidinyldithiocarbamato Mn[N-piperdtc] as (MnS_3). The corresponding passivated films were denoted as CM-1, CM-2, and CM-3. The influence of passivation on the structural, optical, morphological, and photochemical properties of the prepared devices has been investigated. Raman spectra show that the combination of this heterostructure is triggered by the variation in particle size and surface effect, thus resulting in good electronic conductivity. The narrow band gaps could be attributed to good interaction between the passivative materials on the TiO₂ surface. CM-2 cells, stability studies show that the cell is polarized and current flows due to electron migration across the electrolyte and interfaces at this steady state. The cyclic voltammetry (CV) curve for the CM-3 with the highest current density promotes the electrocatalytic activity of the assembled solar cell. The catalytic reactions are further confirmed by the interfacial electron lifetimes in the Bode plots and the impedance spectra. The current-voltage (J-V) analysis suggests that the electrons in the conduction band of TiO₂/CuS recombine with the semiconductor quantum dots (QDs) and the iodolyte HI-30 electrolyte, resulting in 5.20-6.85% photo-conversions.