Organic Electronics

Lecture (Vorlesung)

Since the partially accidental discovery of high electrical conductivity in doped polyacetylene (published in 1977, Nobel Prize in Chemistry 2000), Organic Electronics developed into an interdisciplinary field connecting to physics, chemistry, electrical engineering, and more recently even biology and medicine. The common denominator in all these activities, be it fundamental studies or practical device development, are pi-conjugated, carbon-based materials. Over the years, the community has learned that to really understand the optoelectronic properties of these materials, one cannot simply transfer concepts from inorganic materials; instead formalisms that take into account the unique physical properties of the active molecular materials are needed.

The goals of this lecture are:

• to give understanding of the key concepts underlying the optoelectronic properties of organic (semi)conductors
• to give understanding of the working mechanism of typical organic electronic devices
• to make this understanding both qualitative and quantitative
• to illustrate introduced concepts with recent experimental results, and to introduce some of the commonly employed electrical and optical measurement tools.
• to make connections to (inorganic) solid state physics, thermodynamics, semiconductor physics etc.

Organization:
The course basis consists of weekly lectures (2 hrs/week) that can, but do not have to be combined with tutorials (2 hrs/week) in which the participants actively work with the concepts that are introduced in the lectures. The tutorials are a mixture of assignments, numerical experiments and data analysis from real experiments.

Interested students can register by sending an email to Martijn Kemerink before the start of the semester or (preferred) via uebungen.physik.uni-heidelberg.de here.

The seminar is organized in the winter semester. Further information on dates, times and locations can be found in the LSF system.

Exam and Credits:
For those that only followed the lectures, the exam consists of a regular oral examination; passing gives 2 study credits. For those that also participated in the tutorials, the exam is based on the handed-in answers to assignments and consists of a short (oral) discussion of these answers. This option will give 4 study credits.

Required knowledge:
The course is mainly intended for master students in physics and assumes the student has a basic operational understanding of quantum mechanics, solid state physics and matrix algebra. No prior knowledge on organic electronics, molecular physics or physical chemistry is needed. Students with non-physics backgrounds should contact the teacher before registering.

Topics:

• Quantum chemistry of pi-conjugated materials:
  • energy levels, wave functions
  • band gap formation
  • excitations: polarons, excitons
  • role of spin
  • charge transfer reactions
• Microscopic charge & energy transport
  • disorder, localization, hopping
  • percolation
  • Gaussian disorder models
  • thermoelectricity
• Macroscopic charge transport
  • drift-diffusion & Poisson equations
  • space charge limited transport
  • doping
  • charge injection
  • trapping, recombination, light emission
• Device physics
  • field effect transistors
  • light emitting diodes
  • solar cells
  • thermogenerators

Since I continuously update these lectures, this list is subject to change. For any further information please contact Martijn Kemerink.