Poly(p-phenylene Vinylene) - Applications

Applications

Due to its stability, processability, and electrical and optical properties, PPV has been considered for a wide variety of applications. In 1989 the first polymer-based light emitting diode (LED) was discovered using PPV as the emissive layer. Polymers are speculated to have advantages over molecular materials in LEDs, such as ease of processing, reduced tendency for crystallization, and greater thermal and mechanical stability. Ever since the first breakthrough in 1989, a large number of PPV derivatives have been synthesized and used for LED applications. Although solid-state lasing has yet to be demonstrated in an organic LED, poly (MEH-PPV) has been proven to be a promising laser dye due to its high fluorescence efficiency in solution.

Polyphenylene vinylene is capable of electroluminescence, leading to applications in polymer-based organic light emitting diodes. PPV was used as the emissive layer in the first polymer light-emitting diodes. Devices based on PPV emit yellow-green light, and derivatives of PPV obtained by substitution are often used when light of a different color is required. In presence of even a small amount of oxygen, singlet oxygen is formed during operation, by energy transfer from the excited polymer molecules to oxygen molecules. These oxygen radicals then attack the structure of the polymer, leading to its degradation. Special precautions therefore have to be kept during manufacturing of PPV in order to prevent oxygen contamination.

PPV is also used as an electron-donating material in organic solar cells. Although PPV-based devices suffer from poor absorption and photodegradation, PPV and PPV derivatives (especially MEH-PPV and MDMO-PPV) find frequent application in research cells.