Zinc Oxide–Zinc Phthalocyanine Interface for Hybrid Solar Cells

• Published in: Journal of physical chemistry. C Vol. 116; no. 29; pp. 15439 - 15448
• Main Authors: Mattioli, Giuseppe, Melis, Claudio, Malloci, Giuliano, Filippone, Francesco, Alippi, Paola, Giannozzi, Paolo, Mattoni, Alessandro, Amore Bonapasta, Aldo
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 26-07-2012
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Energy; Exact sciences and technology; Materials science; Nanoscale materials and structures: fabrication and characterization; Natural energy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Other topics in nanoscale materials and structures; Photovoltaic conversion; Physics; Solar cells. Photoelectrochemical cells; Solar energy; Surface and interface electron states; Electronic properties; Electron injection; Nanostructure; Spectral line shift; Redshift; Zinc; Photovoltaic cell; Aggregation; Solar cell; Phenomenological model; Phthalocyanine; Interface properties; Absorption band; Optical properties; Zinc oxide; Ab initio calculations; Interface; Surface potential
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp303781v

The structural, electronic, and optical properties of a hybrid interface formed by zinc phthalocyanine (ZnPc) molecules adsorbed on the (101̅0) zinc oxide (ZnO) surface have been investigated by using ab initio and model potential theoretical methods. In particular, the attention has been focused on the effects of molecular assembling on the interface properties by considering cofacial and planar molecular aggregates on the surface. Present results show that planar aggregations provide a remarkable molecule-to-surface electronic coupling which can favor electron injection toward the substrate. Furthermore, we predict a blue shift of absorption bands in the case of cofacial aggregation and a red shift in the case of nanostructured planar J-stripes, which are in agreement with previous phenomenological models and give a firm theoretical support to observed relationships between red shift and molecular assembling. All together, present results indicate that structural and electronic properties can be achieved in ZnPc-sensitized ZnO surfaces of high potential interest for improving the efficiency of different kinds of hybrid photovoltaic cells.