AIMS AND CONTENT

LEARNING OUTCOMES

Relevance of surfaces and interfaces in Nanoscience and Nanotechnology. The course will introduce: a) the surface excess quantities and thermodynamical properties of surfaces; b) the surface crystallographic structure with relaxation and reconstruction phenomena; c) the surface electronic ground state properties and the surface states; d) the surface magnetic properties. Specific cases for semiconductor, oxide and insulator surfaces, graphene and other ultrathin films will be discussed with respect to dimensionality with extension towards one and zero dimensions, i.e atomic wires, surface steps and clusters. Excited states at surfaces will be treated: surface phonon spectra, surface electronic and magnetic excitations. Connections to plasmonics, Energy harvesting in solar cells and photoinduced chemistry will be stressed. Gas-Surface interaction, physisorption and chemisorption, dynamics of the interaction, adsorption, desorption, sticking and simple catalytic reactions will be discussed. Crystal growth, MBE, CVD, ablation techniques, nanosized films and clusters will be introduced as well as self-assembled monolayers, artificial nanostructures and surface functionalization. Experimental methods for surface characterization, like Scanning Probe Microscopies and Diffraction Methods, as well as Surface Sensitive Electronic and Vibrational Spectroscopies will be introduced.

AIMS AND LEARNING OUTCOMES

Relevance of surfaces and interfaces in Nanoscience and Nanotechnology. The course will introduce: a) the surface excess quantities and thermodynamical properties of surfaces; b) the surface crystallographic structure with relaxation and reconstruction phenomena; c) the surface electronic ground state properties  and the surface states; d) the surface magnetic properties. Specific cases for semiconductor, oxide and insulator surfaces, graphene and other ultrathin films will be discussed with respect to dimensionality with extension towards one and zero dimensions, i.e atomic wires, surface steps and clusters. Excited states at surfaces will be treated: surface phonon spectra, surface electronic and magnetic excitations. Connections to plasmonics, Energy harvesting in solar cells and photoinduced chemistry will be stressed. Gas-Surface interaction, physisorption and chemisorption, dynamics of the interaction, adsorption, desorption, sticking and simple catalytic reactions will be discussed. Crystal growth, MBE, CVD, ablation techniques, nanosized films and clusters will be introduced as well as self-assembled monolayers, artificial nanostructures and surface functionalization. Experimental methods for surface characterization, like Scanning Probe Microscopies and Diffraction Methods, as well as  Surface Sensitive Electronic and Vibrational Spectroscopies will be introduced.

PREREQUISITES

Introduction to solid state properties, principles of Quantum Mechanics

TEACHING METHODS

Theoretical concepts will be itnroduced in frontal lessons. 

Laboratory training will complement them and provide further skills.

Attendance of laboratory is compulsory.

SYLLABUS/CONTENT

Frontal lectures (40 hours):

Surface crystallographic structure.

• The geometric surface plane and the two-dimensional surface lattice, its unit cell and symmetry properties, and surface relaxation and reconstruction.
• Direct and reciprocal lattices.
• Notation of surface structure:  low Miller index surfaces, vicinal surfaces, superlattices.
• Examples of the reconstruction of metal and semiconductor surfaces.
• Modification of the surface structure by physisorption and  chemisorption and crystal growth modes.
• Determination of the surface structure: diffraction methods vs microscopy.
• Low energy electron diffraction (LEED), and treatment of multiple scattering and dynamical LEED.
• Small angle scattering and high resolution in reciprocal space.
• Low energy electron microscopy and scanning probe microscopies (STM, AFM).
• Characterization of surface composition: Auger electron and X-Ray induced photoemission.

Surface Thermodynamics.

• Surface excess quantities.
• Surface energy, surface tension and work needed to create a surface.  
• Surface heat capacity.
• Surface energy and surface composition for alloys segregation.
• Island growth and ripening phenomena.

Surface Lattice Dynamics.

• The Surface phonon spectrum, bulk bands, and surface modes. T
• he Rayleigh wave.
• Surface phonon anomalies.
• Vibrational and thermal desorption spectroscopies.
• Surface Debye temperature.

Surface Electronic properties.

• The jellium model: internal potential and work function.
• The surface dipole layer and the face dependence of the work function.
• Surface band structure, and density of states at the surface and surface states.
• The image states and implication for photochemistry.
• Electronic excitations and  surface plasmons.

Graphene and other two dimensional crystals.

• Electronic properties and lattice dynamics in purely two dimensional systems.

Adsorption of gases and catalysis.

• Self assembled monolayers and artificial nanostructures.
• Physisorption vs Chemisorption.
• Gas surface interaction.
• Precursor states.
• Activated adsorption.
• Examples of catalytic reactions in the heterogeneous phase.  

Laboratory training (12 hours).

• Low energy electron diffraction.
• X ray photoemission and Auger electron spectroscopies.
• Scanning probe microscopies: STM, AFM.

RECOMMENDED READING/BIBLIOGRAPHY

• Gabor A. Somorjai and Yimin Li: Introduction to Surface Chemistry and Catalysis, second edition, Wiley.
• Teacher’s slides and other material will be provided to the students by the teacher.

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

According to the timetable reported here 

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

The exam will consist in an oral interview. The studnets will be asked to anwer two questions about:

a) the theoretical concepts and their application in material science

b) the experimental methods shown in the laboratory part.

ASSESSMENT METHODS

The level reached by the students will be assessed considering:

a) the adequacy of the language used to answer the questions and the clarity of the graphs used to answer them.

b) the capability to resume clearly the methods used in the experimental part of the course.

c) the knowledgde of the basic concepts of surface science covered in the theoretical lessons.

d) the capability to identify the experimental methods requried for the measurement of the main observables (e.g: surface structure, phonon dispersion, electronic excitations, adsorption properties) 

FURTHER INFORMATION

Students with disabilities and learning disabilities (SLD): Students with disabilities or specific learning disabilities (SLD) may request adaptations for exams. Certification must be uploaded to the University website at servizionline.unige.it in the "Students" section. The documentation will be verified by the University's Services for the Inclusion of Students with Disabilities and SLD ((https://rubrica.unige.it/strutture/struttura/100111). Subsequently, well in advance (at least 7 days) of the exam date, the appropriate online form must be completed (https://modulionline.unige.it/richiesta-adattamenti#no-back).
For further information on requesting services and adaptations, please visit the link https://unige.it/disabilita-dsa/richiesta-servizi