Case Studies Interface Conditioning

As interfacial properties control charge transfer, surface recombination, and stabihty, their optimization is a key to effldent and stable operation in solar energy-converting structures and devices. The examples considered here are related to the development of either photovoltaic or photoelectrocatalytic efficient systems that wiU be described in Sections 2.5 and 2.6. The case studies begin with the more detailed continuation of the above described formation of nanotopographies on Si 

The in situ interface conditioning of p-lnP by photoelectrochemical processes, described in Section 2.4.2, is a key procedure for the preparation of efficient and stable photovoltaic and photoelectrocatalytic solar cells and surface analyses wiU be presented that describe the induced chemical and electronic changes. The ternary chalcopyrites CulnSe2 and CulnS2 have meanwhile been developed for use in commercially available solid-state solar cells. For the sulfide-based cell, the use of a toxic KCN etch step of Cu-rich CulnS2 to remove Cu-S surface phases is considered as deleterious for wide-scale application and an electrochemical method will be presented in Section 2.4.3 that replaces the chemical etching procedure. 

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In this book, the processes at solid/liquid interfaces of soil and rock, in most cases under environmental conditions, will be discussed. A scientifically correct description of interfacial processes requires the study of the properties of solid and liquid phases and the interface, as well as the interactions of these phases. Previous books typically focused on selected aspects of the subject, such as, for example, the properties of the solid phase or the interactions of selected substances such as heavy metal ions with soil/rock. We intend to present a comprehensive treatment of the soil-liquid-interface system, emphasizing the importance of the chemical species produced in a geological material/solution/interface interaction. We recommend the book to all chemists, geologists, and soil scientists working in interfacial, environmental, and soil sciences. 

AB diblock copolymers in the presence of a selective surface can form an adsorbed layer, which is a planar form of aggregation or self-assembly. This is very useful in the manipulation of the surface properties of solid surfaces, especially those that are employed in liquid media. Several situations have been studied both theoretically and experimentally, among them the case of a selective surface but a nonselective solvent [75] which results in swelling of both the anchor and the buoy layers. However, we concentrate on the situation most closely related to the micelle conditions just discussed, namely, adsorption from a selective solvent. Our theoretical discussion is adapted and abbreviated from that of Marques et al. [76], who considered many features not discussed here. They began their analysis from the grand canonical free energy of a block copolymer layer in equilibrium with a reservoir containing soluble block copolymer at chemical potential peK. They also considered the possible effects of micellization in solution on the adsorption process [61]. We assume in this presentation that the anchor layer is in a solvent-free, melt state above Tg. The anchor layer is assumed to be thin and smooth, with a sharp interface between it and the solvent swollen buoy layer. 

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