Abstract
Quantum dot-sensitized solar cells (QDSSCs) have emerged as promising photovoltaic devices, in which the counter electrode (CE) plays a crucial role in the catalytic reduction of S(n) (2-) and charge transfer. Based on a precursor-directed strategy, this study reports a simple and cost-effective solvothermal method for the synthesis of morphology-controlled CuCo(2)S(4) nanomaterials without templates and structure-directing agents, including flower-like (f-CuCo(2)S(4)), nanosheet-like (n-CuCo(2)S(4)), nanoparticle-like (p-CuCo(2)S(4)), and microsphere-like (m-CuCo(2)S(4)) structures. The effects of CuCo(2)S(4) CEs with different morphologies on the photovoltaic performance of QDSSCs were also systematically investigated. Among them, the f-CuCo(2)S(4) CE exhibited the highest specific surface area and the best catalytic performance, resulting in a power conversion efficiency (PCE) of 7.42% for QDSSCs, which is 55% higher than that of materials with other morphologies. Electrochemical analysis confirmed that it delivered the lowest charge transfer resistance (R (ct) = 0.076 Ω) and the highest electrocatalytic activity. This work highlights the importance of morphology control for optimizing the performance of CEs for efficient QDSSCs.