Investigation of Quantum Dot-Based Photovoltaic Devices for Efficient Solar Energy Conversion.

Abstract

Quantum dot-based photovoltaic (QDPV) devices have attracted significant attention as a next-generation solution for efficient solar energy conversion due to their unique optoelectronic properties and potential for low-cost fabrication. This study investigates the performance and efficiency of quantum dot-based solar cells by analyzing material characteristics, device architecture, and charge transport mechanisms. Semiconductor quantum dots such as lead sulfide (PbS) and cadmium selenide (CdSe) are explored due to their tunable bandgap, which enables enhanced absorption across a broad solar spectrum, including both visible and near-infrared regions. The ability of quantum dots to exhibit multiple exciton generation further enhances carrier production, offering the potential to exceed the efficiency limits of conventional silicon-based solar cells. The proposed photovoltaic device is designed using a multilayer architecture comprising a transparent conductive oxide layer, electron transport layer, quantum dot absorber layer, hole transport layer, and metal electrode. Simulation and analytical modeling are employed under standard illumination conditions to evaluate key performance parameters, including power conversion efficiency, open-circuit voltage, short-circuit current density, and fill factor. The results demonstrate that optimization of quantum dot size, layer thickness, and interface properties significantly improves light absorption and charge carrier dynamics. Furthermore, the study highlights the impact of material selection and device engineering on minimizing recombination losses and enhancing overall device stability. Comparative analysis indicates that PbS-based devices are more effective in harvesting infrared light, whereas CdSe-based devices perform better in the visible range. Despite challenges such as material toxicity and long-term stability, quantum dot photovoltaics offer a promising pathway toward high-efficiency, flexible, and scalable solar energy solutions for future renewable energy systems.