Development and Study of Hybrid Photovoltaic Cells

Hybrid photovoltaic cells are electronic devices designed for conversions of light into the noblest form of energy, electricity. They are cost effective alternatives of conventional silicon solar cells, but their efficiency of the power conversion has been low so far. However, they can potentially surpass the conventional silicon cells not only in the production cost, but also in performance because of their architecture combines unique properties of organic and inorganic materials. The design of these devices is based on particle size of nanostructures and extremely large interfaces that can lead to photo-absorption in wide ranges of light radiation and effective exciton dissociation.This project is engaged in development and investigation of hybrid photovoltaic cells that will lead to the devices with effective light conversion to electricity. The design of organic/inorganic photocell structures with implementation of novel fabrication approaches and study of nanomaterial interfaces in the device architecture is the essence of the project. Particularly ZnO and Al:ZnO (AZO) nanostructures with different morphologies including aligned vertical ZnO nanowires and flocky nanorods as well as silicon nanowires prepared by simple chemical etching methods will be investigated and used in the designed photovoltaic device structures. The ZnO and AZO nanomaterials, inherently n-type semiconductors, will be infiltrated by organic p-type conducting materials to provide large p-n heterojunctions. The researchers estimate the size of organic/inorganic heterojunction interface to be about 120m2per gram of ZnO nanowires. The size of the heterojunction can further be enlarged by using flocky ZnO nanorods which the researchers recently developed. The problem of the size of the heterojunction interface and the infiltration by organic p-semiconductors using novel methods will be investigated specifically for wetability, electronic interfacial structures, effective dissociation of photo-induced excitons, their diffusion length and interfacial field separation. It is foreseen that within the designed photovoltaic cells the recombination process will be suppressed considerably to give rise to the high power efficiency of light– electricity conversion. Optimizing the electrode configuration and possible suppression of charge recombination in different parts of the devices and exploring the interfaces in the hybrid photovoltaic devices will lead to considerable improving the efficiency of the design devices.