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The investigation of the interfacial phase transitions in fluid systems with short-range intermetallic interactions are of great interest. The phenomena were studied in two systems exhibiting a liquid-liquid miscibility gap: at the fluid/wall interface in fluid KxKCl1-x and at the fluid/vacuum interface of the Ga1 xBix alloys. To characterize the interfacial changes of the ultra thin films (composition, thickness and their evolution with time) the spectroscopic ellipsometry was performed over a wide spectral range. Whereas in the experiments on KxKCl1-x an existing ellipsometer could be used, a completely new UHV-apparatus including the in-situ phase modulation ellipsometer had to be developed for Ga1 xBix alloys. For the KxKCl1-x system new results on complete wetting at solid-liquid coexistence as well as in the homogenous liquid phase (prewetting) are presented. The spectra show the typical F center absorption which indicates that the film is a salt-rich phase. The thickness strongly increases approaching the monotectic from 30 to 440 nm, which is in agreement with the tetra point wetting scenario. For this interpretation a quantitative description of the excess Gibbs energy has been developed. For the Ga1 xBix system the results on complete wetting, surface freezing and oscillatory interfacial instabilities are presented. The high-precision spectra have been recorded approaching the liquid-liquid miscibility. These spectra have been modeled using a Ga-Bi effective medium approximation for the substrate covered by a film of liquid Bi. The measurements give evidence of tetra point wetting in the Ga-Bi system. First ellipsometric study of the surface freezing in Ga-Bi has been performed. Within the miscibility gap a very interesting effect of surface and bulk oscillatory instability was observed. The details of this process at present are not well understood, but a qualitative description is given.

molten salt --- surface phase transition --- spectroscopic ellipsometry --- Ga-Bi alloys

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This book contains the articles collected for the Special Issue entitled "Micro-nano Surface Functionalization of Materials and Thin Films for Optical Applications" in the journal Coatings (ISSN 2079-6412). These selected articles provide a meaningful overview of recent advances and concepts beyond the state-of-the-art regarding surface functionalization of materials and deposition of thin films to be used in optical applications. The aim was to cover all relevant aspects of the topic (simulation, design, fabrication, characterization and applications) with a special emphasis on non-conventional methods for surface modification of materials, combinations of mature fabrication routes with emerging technologies (i.e., additive manufacturing) and large-area fabrication concepts to pave the way to an industrial utilization of the developed materials. This overview comprises the recent work of reputed scientists from Germany, Austria, Spain and India on: - New developments on the scale-up deposition of transparent conductive materials by magnetron sputtering,- Design of hierarchical surface structures at different scale lengths for nanoimprinting of optical nano- and micro-structures, - Non-conventional preparation of rutile-type TiO2 films at room temperature for optical applications on heat-sensitive substrates, - Design of spectrally selective solar absorber coatings based on computational simulation and ellipsometry measurements.

reactive magnetron sputtering --- transparent conductive oxide --- electronic transport --- doping efficiency --- tin dioxide --- Nanoimprint lithography --- UV-NIL --- reversal NIL --- liquid transfer imprint lithography --- hierarchical structures --- optical micro- and nanostructures --- ITO thin films --- magnetron sputtering --- low temperature deposition --- oxygen flow --- microstructure --- optoelectronic properties --- transparent heaters --- titanium oxide films --- filtered cathodic vacuum arc --- rutile --- optical coatings --- spectrally selective absorber --- multilayer stack --- spectroscopic ellipsometry --- optical constants --- simulation

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This book contains the articles collected for the Special Issue entitled "Micro-nano Surface Functionalization of Materials and Thin Films for Optical Applications" in the journal Coatings (ISSN 2079-6412). These selected articles provide a meaningful overview of recent advances and concepts beyond the state-of-the-art regarding surface functionalization of materials and deposition of thin films to be used in optical applications. The aim was to cover all relevant aspects of the topic (simulation, design, fabrication, characterization and applications) with a special emphasis on non-conventional methods for surface modification of materials, combinations of mature fabrication routes with emerging technologies (i.e., additive manufacturing) and large-area fabrication concepts to pave the way to an industrial utilization of the developed materials. This overview comprises the recent work of reputed scientists from Germany, Austria, Spain and India on: - New developments on the scale-up deposition of transparent conductive materials by magnetron sputtering,- Design of hierarchical surface structures at different scale lengths for nanoimprinting of optical nano- and micro-structures, - Non-conventional preparation of rutile-type TiO2 films at room temperature for optical applications on heat-sensitive substrates, - Design of spectrally selective solar absorber coatings based on computational simulation and ellipsometry measurements.

Research & information: general --- reactive magnetron sputtering --- transparent conductive oxide --- electronic transport --- doping efficiency --- tin dioxide --- Nanoimprint lithography --- UV-NIL --- reversal NIL --- liquid transfer imprint lithography --- hierarchical structures --- optical micro- and nanostructures --- ITO thin films --- magnetron sputtering --- low temperature deposition --- oxygen flow --- microstructure --- optoelectronic properties --- transparent heaters --- titanium oxide films --- filtered cathodic vacuum arc --- rutile --- optical coatings --- spectrally selective absorber --- multilayer stack --- spectroscopic ellipsometry --- optical constants --- simulation

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This book is composed of 6 papers. The first paper reports a novel technique for the selective emitter formation by controlling the surface morphology of Si wafers. Selective emitter (SE) technology has attracted renewed attention in the Si solar cell industry to achieve an improved conversion efficiency of passivated-emitter rear-contact (PERC) cells. In the second paper, the temperature dependence of the parameters was compared through the PERC of the industrial-scale solar cells. As a result of their analysis, PERC cells showed different temperature dependence for the fill factor loss as temperatures rose. The third paper reports the effects of carrier selective front contact layer and defect state of hydrogenated amorphous silicon passivation layer/n-type crystalline silicon interface. The results demonstrated the effects of band offset determined by band bending at the interface of the passivation layer and carrier selective front contact layer. In addition, the nc-SiOx: H CSFC layer not only reduces parasitic absorption loss but also has a tunneling effect and field-effect passivation. The fourth paper reports excimer laser annealing of hydrogenated amorphous silicon film for TOPCon solar cell application. This paper analyzes the crystallization of a-Si:H via excimer laser annealing (ELA) and compared this process with conventional thermal annealing. The fifth paper reports the contact mechanism between Ag–Al and Si and the change in contact resistance (Rc) by varying the firing profile. Rc was measured by varying the belt speed and peak temperature of the fast-firing furnace. The sixth paper reports a silicon tandem heterojunction solar cell based on a ZnO/Cu2O subcell and a c-Si bottom subcell using electro-optical numerical modeling. The buffer layer affinity and mobility together with a low conduction band offset for the heterojunction are discussed, as well as spectral properties of the device model.

fill factor loss analysis --- double-diode model --- PERC --- temperature dependence --- recombination current density --- parasitic resistance --- carrier selective contact --- rear emitter heterojunction --- passivation --- crystallinity --- thermal annealing --- excimer laser annealing --- amorphous hydrogenated silicon film --- metallization --- contact formation --- Ag/Al paste --- p+ emitter --- N-type bifacial solar cells --- silicon tandem heterojunction solar cell --- N-doped Cu2O absorber layer --- Al:ZnO (AZO) --- numerical electro-optical modeling --- scanning electron microscopy (SEM) --- atomic force microscopy (AFM) --- X-ray diffraction (XRD) --- spectroscopic ellipsometry (SE) --- Fourier-transform infrared (FTIR) spectroscopy --- degradation degree --- failure rate --- selective emitter --- surface morphology --- doping process --- solar cell

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This book is composed of 6 papers. The first paper reports a novel technique for the selective emitter formation by controlling the surface morphology of Si wafers. Selective emitter (SE) technology has attracted renewed attention in the Si solar cell industry to achieve an improved conversion efficiency of passivated-emitter rear-contact (PERC) cells. In the second paper, the temperature dependence of the parameters was compared through the PERC of the industrial-scale solar cells. As a result of their analysis, PERC cells showed different temperature dependence for the fill factor loss as temperatures rose. The third paper reports the effects of carrier selective front contact layer and defect state of hydrogenated amorphous silicon passivation layer/n-type crystalline silicon interface. The results demonstrated the effects of band offset determined by band bending at the interface of the passivation layer and carrier selective front contact layer. In addition, the nc-SiOx: H CSFC layer not only reduces parasitic absorption loss but also has a tunneling effect and field-effect passivation. The fourth paper reports excimer laser annealing of hydrogenated amorphous silicon film for TOPCon solar cell application. This paper analyzes the crystallization of a-Si:H via excimer laser annealing (ELA) and compared this process with conventional thermal annealing. The fifth paper reports the contact mechanism between Ag–Al and Si and the change in contact resistance (Rc) by varying the firing profile. Rc was measured by varying the belt speed and peak temperature of the fast-firing furnace. The sixth paper reports a silicon tandem heterojunction solar cell based on a ZnO/Cu2O subcell and a c-Si bottom subcell using electro-optical numerical modeling. The buffer layer affinity and mobility together with a low conduction band offset for the heterojunction are discussed, as well as spectral properties of the device model.

History of engineering & technology --- fill factor loss analysis --- double-diode model --- PERC --- temperature dependence --- recombination current density --- parasitic resistance --- carrier selective contact --- rear emitter heterojunction --- passivation --- crystallinity --- thermal annealing --- excimer laser annealing --- amorphous hydrogenated silicon film --- metallization --- contact formation --- Ag/Al paste --- p+ emitter --- N-type bifacial solar cells --- silicon tandem heterojunction solar cell --- N-doped Cu2O absorber layer --- Al:ZnO (AZO) --- numerical electro-optical modeling --- scanning electron microscopy (SEM) --- atomic force microscopy (AFM) --- X-ray diffraction (XRD) --- spectroscopic ellipsometry (SE) --- Fourier-transform infrared (FTIR) spectroscopy --- degradation degree --- failure rate --- selective emitter --- surface morphology --- doping process --- solar cell