Enhancing optoelectronic components with phosphorous

A team of researchers from the Dresden University of Technology, led by Professor Jan. J Weigand, have developed a method to introduce phosphorous and nitrogen atoms into polycyclic molecules. This method could pave the way for the development of new materials with specific optoelectronic properties that are suitable for applications in organic semiconductor technologies such as OLEDs and sensors. The research findings have been published in the journal CHEM.

Polyaromatic hydrocarbons, abbreviated as PAHs, play a key role in many optoelectronic applications, including chemical sensors, organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) and organic solar cells. Researchers are continually exploring the substitution of various elements beyond traditional carbon to optimise device performance and versatility. While substitution with boron (B), nitrogen (N), oxygen (O) and sulfur (S) has already undergone extensive research, the integration of phosphorous (P) in combination with nitrogen (N) remains a challenge.

Weigand and his research team recently developed an innovative method to selectively introduce phosphorous and nitrogen atoms into polyaromatic systems. “This method allowed the synthesis of a wide range of P/N-substituted compounds, whose physicochemical properties were thoroughly investigated in collaboration with physicists from TUD. Through the combination of material simulations and spectroscopic measurements, we were able to gain fundamental insights into the structure-property relationships of the obtained compounds,” Weigand said.

The new method provides access to the class of azaphospholes, which were previously only accessible in a cumbersome manner and in low yields. Therefore, they were not considered for optoelectronic applications until now.

“By deliberately combining phosphorus and nitrogen, we hope to be able to control the electronic and optical properties of these compounds in a way that was not possible before. This opens up exciting prospects for future applications in optoelectronics and beyond,” Sebastian Reineke, head of the Light-Emitting and eXcitonic Organic Semiconductors Group at TUD, said.

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