ABSTRACT
Rates ................................................................................... 271 6.2.6 Simplifying the Pair Model for the Description of Incoherent
Pair Propagation ............................................................................... 271 6.2.7 Macroscopic Phenomena Determined
by Spin-Dependent Pair Transitions ................................................. 272 6.2.7.1 Fundamental Efciency Limitations of OLEDs ................ 272 6.2.7.2 Spin Mixing ....................................................................... 272 6.2.7.3 Magnetoresistance ............................................................. 273
6.3 The Investigation of Spin-Dependent Transitions ........................................ 273 6.3.1 Technical Requirements ................................................................... 273
6.3.1.1 Magnetic Resonance Excitation ......................................... 274 6.3.1.2 Detection of Spin-Dependent Rates ................................... 275
Today, organic semiconductors are used commercially for a variety of organic electronic devices, including organic light-emitting diodes (OLEDs),1,2 organic electronic displays,3 –6 and organic solar cells.7-11 Some of the technological advantages organic electronics provide include excellent energy efciency, physical exibility, and extraordinary economical production. Using organic materials for solar cells provides a number of important advantages over conventional inorganic approaches: the material is exible and lightweight, allowing for novel installation and applications; it can be printed onto a exible substrate in a reel-to-reel process, enabling large-scale production; organic solar cells are reasonably energy efcient and, while they still trail the efciencies of inorganic solar cells,12 their signicantly lower cost makes them highly competitive.
