Organic semiconductors are promising for the development of many applications including in solid state lighting, flexible displays and organic-based lasing. However, a critical factor limiting their utility is their inherently low stability relative to inorganic materials. This instability causes organic molecules to be susceptible to oxygen damage in an irreversible process known as photo-bleaching. This effect necessitates the development of highly impermeable encapsulation strategies and limits device lifetimes. Plasmonic engineering offers one avenue to alter the decay rates of fluorophores and modify the emission from single molecules and thin films. Here, we demonstrate that by carefully engineering the properties of ultra-thin gold films to match the plasmon with the emission of organic molecules a photostability enhancement of more than 60-fold can be achieved. As an example, we successfully demonstrated that OPPV-13, an oligomer of poly [2-methoxy-5(2'-ethylhexyloxy)-1,4-phenylene]vinylene, deposited on 2 nm thick Au substrates retains its fluorescence under constant illumination in ambient conditions for 45 minutes compared to less than 2 minutes when it is deposited on glass substrates. The underlying mechanism of this remarkable enhanced photostability is probed using a variety of microscopy-based tools and extensions to other opto-electronic materials are described.
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