Efficient Sb 2 S 3 ‐Sensitized Solar Cells Via Single‐Step Deposition of Sb 2 S 3 Using S/Sb‐Ratio‐Controlled SbCl 3 ‐Thiourea Complex Solution

To replace the conventional chemical bath deposition method, which is time‐consuming and has a high impurity level, a chemical single‐step deposition process employing a S/Sb ratio‐controlled SbCl 3 ‐thiourea complex solution is introduced to load Sb 2 S 3 into a mesoporous TiO 2 electrode. This technique enables the fabrication of efficient and reproducible Sb 2 S 3 ‐sensitzed inorganic–organic heterojunction hybrid solar cells with hole‐conducting conjugated polymers. The most efficient cell exhibits a short‐circuit current density of 16.1 mA cm −2 , an open circuit voltage of 595.5 mV, and a fill factor of 66.5%, yielding a power conversion efficiency of ≈6.4% at standard AM1.5G condition (100 mW cm −2 ).