Silicon based chips and transistors have been at the heart of all electronic devices since the 1950s. Driven by economic and environmental factors, and by the need for renewable energy resources, there is currently an enormous scientific and technological interest in transitioning away from silicon based electronics to new organic electronic devices. Just like living organisms, organic electronics use carbon in complex molecules as their key functional component. These new organic electronic devices are less expensive, more environmentally friendly and better recyclable than the older ones. Today the most commercially successful organic electronic devices are OLEDs (organic light emitting diodes) found in smart phone displays. Other promising devices include very inexpensive solar cells for low-cost and low-carbon electricity generation, and ultra-efficient building lighting which could substantially lower electricity consumption.
Yajun Gao and Professor Paul H.M. van Loosdrecht from the University of Cologne have now made substantial progress in this field in collaboration with researchers from Jilin University (China) and the University of Nottingham (UK). The team was able to design an organic electronic device in which charge generated by light lived approximately 10,000 times longer than was previously thought possible. They did this by designing a small device based on organic molecules in which the built-in electric field creates a well which traps and protects charge carriers. This opens up the possibility of creating entirely new classes of organic electronic devices, such as ultra-sensitive photo detectors to image distant stars, or flexible memory elements which could be used in wearable computers. The findings of the research team are described in the article "Organic Electronics: Engineering Ultra Long Charge Carrier Lifetimes in Organic Electronic Devices at Room Temperature", published in the journal Advanced Materials Interfaces.