Optimizing the Photovoltaic Properties of CdTe Quantum Dot–Porphyrin Nanocomposites: A Theoretical Study

Abstract

By using the self-consistent charge density functional tight binding method, we explore the photovoltaic properties of CdTe quantum dot (CdTeQD)–porphyrin nanocomposites. It is well-known that for dye-sensitized solar cell (DSSCs) applications, the composite system should have a type-II band alignment that hinders the recombination of charge carriers, thereby improving the photovoltaic performance. The emphasis of our tight-binding calculations is to find the suitable CdTeQD–porphyrin nanocomposites that can offer better performance for solar energy conversion. By analyzing the electronic energy levels of the composite systems we have shown that the axially coordinated Zn-tetraphenylporphyrin (ZnTPP) functionalized CdTe quantum dot (ZnTPP–CdTeQD) nanocomposites are really promising materials for application in DSSCs, as they produce type-II band alignment for all the composites irrespective of the size of CdTeQDs. The time-dependent density functional theory (TDDFT) calculations demonstrate that the size ...