Herein we demonstrate for the first time, the combination of PbS with CdSe/CdS/TiO2 and exploring the impact of manganese (Mn) on PbS (lead sulfide) quantum dot-sensitized solar cells (QDSSCs). Photo-anodes were sensitized with different percentages of Mn content (5, 10 and 15%) on PbS/CdS/CdSe using a simple successive ion layer adsorption and reaction (SILAR) technique. The performance of the QDSSCs is examined in detail using polysulfide electrolyte and a copper sulfide (CuS) counter electrode. The optimized percentage of Mn content on PbS/CdS/CdSe electrode results in higher efficiency compared to bare PbS/CdS/CdSe-sensitized QDs. This is confirmed with photovoltaic studies and electrochemical impedance spectroscopy. The 10% Mn-doped PbS/CdS/CdSe electrode exhibits short circuit current density of 17.34 mA cm2 with an enhanced power to conversion efficiency (η) of 4.25% under 1 sun illumination (AM 1.5 G, 100 mW cm−2).