A novel inorganic spinel compound with formula Zn0.5184La0.7859Ce0.3994Al1.0026O4 (ZLCA) was synthesized by the gel combustion method and its exact formula was approved by the XPS analysis. The TEM image exhibited that the ZLCA NPs were very fine, spherical and slightly agglomerated particles with their particle size changed in the range of similar to 5-20 nm. Then, several quantum dot-sensitized solar cells (QDSSCs) were fabricated using this new compound which was doped into the TiO2 pastes of photoanodes and subsequently the CdS, CdS and ZnS layers were deposited on the ZLCA-doped TiO2 layer by the SILAR and the CBD methods. Results indicated that the photovoltaic parameters of the optimized cell (eta = 3.50%, J(sc) = 11.690 mA.cm(2)) were boosted compared with those of the reference cell which was free of ZLCA NPs (eta = 2.14%, J(sc) = 7.075 mA.cm(2)) indicating rather high improvements of approximately 64 and 65% in the efficiency and short-circuit current density, respectively. The UV-Vis absorption spectra of all nanocomposite photoanodes revealed broad absorption bands between similar to 320 and 600 nm. The lowest intensity of the photoluminescence peak for the CdSe cell fabricated using 0.6%ZLCA suggested that it had the least charge recombination and the easiest electron transfer which was confirmed by the J-V and efficiency results. The Electrochemical impedance spectra (EIS) illustrated that the charge transfer resistances (R-CT) of cells were dropped by addition of the ZLCA into the TiO2 compared with that of the cell made without using ZLCA NPs. The R-CT resistance was 1900 Omega for pure TiO2 but it was decreased to 81.6 Omega in the optimized cell containing 0.6%wt of ZLCA. Thus, it could be decided that doping 0.6%wt ZLCA was appropriate to attain suitable photocurrent efficiency for the QDSSCs because it was used in a minimum quantity to accelerate the electron transport, decrease the recombination and increase the cell efficiency. (C) 2018 Elsevier B.V. All rights reserved.