Hybrid solar cells with inorganic nanoparticles: investigation of the role of nanoparticles and development of devices with higher efficiencies

Abstract

Solar cells based on organic semiconductor materials have achieved energy conversion efficiencies up to 5-6%. This kind of technology enables the production of low cost, flexible devices, with different shapes and sizes, due to their simple assembly and use of inexpensive materials. Recently, hybrid organic-inorganic systems obtained from the mixture of inorganic nanoparticles and conducting polymers have also been used in solar cells. In these systems, the nanoparticles may contribute both to charge transport (due to their usually high charge mobility) and the increase in light-harvesting, thus contributing to improve the photocurrent and efficiency of devices. However, a better understanding of the processes of charge generation and transport in the device, and the synthesis of novel materials are still necessary to make this technology more competitive. This project consists of the development of hybrid solar cells based on the incorporation of different inorganic semiconductor nanoparticles in the mixture of poly(3-hexylthiophene) and a fullerene derivative. Doped-ZnS spherical nanoparticles will be synthesized, aiming at the investigation of the role of these nanoparticles in charge transport when they are incorporated in organic solar cells. Nanowires of InAsP, which can present different absorption characteristics according to the composition ratio between elements of groups III and V, will also be prepared and introduced in the solar cells, to investigate their effect in light-harvesting and device performance. Once the role of the different types of nanoparticles is determined, the systems with best performance will be employed in the assembly/development of new devices with different architectures, especially in the so-called Tandem architecture (series connected cells), in order to produce high efficiency hybrid solar cells. (AU)