-bonding allows for electronic excitations in the visible spectral range. Key Concepts in Organic Semiconductor Physics

Note: For a more detailed academic overview, including equations on charge transport (Marcus theory) and device efficiency, specialized textbooks or authorized PDF review articles such as "Physics of Organic Semiconductors" by W. Brütting are recommended.

When an organic semiconductor absorbs a photon, it doesn't immediately create a free electron and hole. Instead, it creates an —a bound electron-hole pair held together by strong electrostatic (Coulombic) attraction.

OLEDs operate by injecting electrons and holes from electrodes into the organic layers, where they form excitons that emit light.

In inorganic crystals, charges move as delocalized waves through periodic energy bands (band transport). In organic solids, the weak Van der Waals interactions create significant structural disorder, altering how charges move.

Organic semiconductors, however, are composed of carbon-based molecules or polymers with extended π-conjugated systems. This structure leads to a unique set of electronic, optical, and mechanical properties that are revolutionizing modern electronics. Unlike their rigid inorganic counterparts, organic semiconductors are flexible, lightweight, and can be processed using low-cost solution-based methods, such as printing, similar to newspaper ink. This opens the door to technologies like flexible displays, wearable sensors, and even electronic paper.