cod. 1008510

Academic year 2019/20
1° year of course - First semester
Academic discipline
Chimica fisica (CHIM/02)
A scelta dello studente
Type of training activity
Student's choice
48 hours
of face-to-face activities
6 credits
hub: PARMA
course unit

Learning objectives

Knowledge and understanding: the students will acquire basic knowledge in the processes that govern the behaviour of plastic devices, as well as an up to date knowledge on the current state of the art in the field.
Applying knowledge and understanding: the students will acquire the tools required to critically read and understand the literature in the field of plastic optoelectronic, and to smoothly integrate in a research laboratory in the same field.
Learning skills: the student will acquire methodological competences to understand basic phenomena in organic materials as relevant to the development of devices (OLED, solar celles etc)
Communication skills: Mastering of the specialistic language as to allow the student to interact with experts in field of plastic devices and to effectively transfer knowledge also to non-specialized audience.


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Course unit content

An introduction to the physics and chemistry of optoelectronic devices based on organic (plastic) materials. Fundamental concepts and current state of the art.

Full programme

1) Introduction - 6 hours
a. Inorganic semiconductors
b. Organic semiconducting (macro)molecules
i. orbitals and conjugation
ii. Excitations: excitons and polarons
iii. Exciton spin: singlets and triplets
iv. Synopsis electronic and optical processes
v. Optical properties: a few examples
1. EG (Energy Gap) vs. molecular weight
2. Electron-phonon coupling: vibrational structure and thermochromism
3. Förster transfer and Site-Selective Photoluminescence Spectroscopy
vi. Summary of optical properties

2) Organic light-emitting diodes (LEDs) - 15 hours
a. Structure
b. Fundamental processes
i. Charge injection
ii. Charge transport
iii. Exciton formation
1. Mutual capture
2. Exciton characteristics (binding energy, spin-multiplicity, capture cross-section)
iv. Exciton decay
1. Radiative and non-radiative decay
2. Exciton lifetime
3. Efficiency
c. Characterisation of PLEDs
i. Relevant performance parameters
ii. Characterising metal-semiconductor contacts: electroabsorption measurements as a non-invasive tool for the study of the energy level line up in finished devices
d. Practical implementations
i. Anodes
ii. Cathodes
iii. Active materials
1. Singlet emitters
2. Triplet emitters – enhanced spin-orbit coupling via doping with heavy metals/rare-earth ligands
3. Blends: achieving the best of all worlds
iv. Fabrication technology: the advantage of solution processability
1. Spin-coating
2. Ink-jet printing (IJP)
3. Screen-printing and other examples
e. State-of-the-art devices and future prospects
1. Thermally activated delayed fluorescence (TADF)
2. Aggregation-induced emission (AIE)
3. Purely organic phosphorescent materials
4. Flexible electronics and "tattoo-electronics"

3) Organic photovoltaic diodes (PVDs) - 6 hours
a. Fundamental process
i. Exciton absorption
ii. Exciton dissociation
iii. Charge collection
b. Characterisation of PVDs
i. Relevant performance parameters
c. Examples of polymer-based PVDs
1. Polymer-polymer heterojunctions
a. Enhanced dissociation at type II heterojunctions
b. preparation methods: polymer blends and spontaneous phase separation
2. C60-polymer structures
3. Heterojunctions with nanocrystals, nanorods, etc.
d. State-of-the-art devices and future prospects

4) Organic field-effect transistors (FETs) - 6 hours
a. Structure
b. Fundamental processes
i. Channel formation
ii. Charge transport
c. Characterisation
i. Relevant performance parameters
d. Examples of successful strategies
e. State-of-the-art devices and future prospects

5) Supramolecular structures and dendrimers - 6 hours
a. Introduction to secondary (non covalent) interactions and their role in organic solids
b. Insulated molecular wires, IMWs and threaded molecular wires (TMWs).
c. Dendrimers and dendronised materials
d. Potential applications

6) Near-infrared (NIR) emitting and absorbing materials - 6 hours
a. Overview
i. Motivation
ii. Inorganic or hybrid emitters / absorbers
iii. Phosphorescent emitters
b. Challenges: the energy gap "rule"
c. Materials not leveraging triplet-assisted photophysics
d. Current state-of-the-art


- Electronic Processes in Organic Crystals and Polymers, M. Pope, C. Swenberg, Oxford University Press, 2nd ed., Oxford, 1999
- Physics of Solar Cells, P Wurfel Wiley-VCH, Weinheim, 2005
- Organic Electronics, H Klauk, ed. Wiley-VCH, Weinheim, 2006
- slides

Teaching methods

Frontal lessons in English.

Assessment methods and criteria

Oral examination.

Other information

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