Scientists at North Dakota State University have recently developed a family of novel organometallic materials that have unique optical properties that make it ideal for use in optical switches, organic light emitting devices (OLED), and optical sensors.

Illustration showing structures of the synthesized diimine or terdentate platinum complexes bearing fluorenyl component.
This invention revolves around platinum terdentate and bidentate complexes designed, characterized, and synthesized by the inventors. These complexes exhibit broad and strong reverse saturable absorption and/or two-photon absorption in the visible and the near-IR region with excellent solubility in organic solvents.

They also exhibit high-efficiency emission at room temperature. The color and/or the emission of the complexes could change upon physical (temperature) or chemical (pH values, anions, cations, volatile organic vapors, etc.) stimuli. The novelty in this invention is the introduction of substituted fluorenyl unit to the platinum complexes in order to increase the emission efficiency, adjust the solubility, and enhance the two-photon absorption in the near-IR region.

Optical-limiting materials are nonlinear optical materials that can transmit most of the light at low intensities, but absorb, reflect, refract, or scatter light at high incident intensities for the creation of optical sensors, as well as other applications such as organic light emitting diodes (OLEDS) with higher efficiency and optical switching applications such as telecommunications and computing.

Nonlinear absorption, particularly reverse saturable absorption and two-photon absorption, has long been recognized as useful for optical limiting. However, it has not previously been possible to design molecules that exhibit large nonlinear absorption. To remedy this deficiency, the relationship between nonlinear absorption and molecular structure has been explored. Organic/metallo-organic complexes are ideal for this application because of their large, fast, and broadband optical nonlinearity. In addition, the chemical structures of these complexes can be easily modified.

For more information, visit 

Lighting Technology Magazine

This article first appeared in the September, 2012 issue of Lighting Technology Magazine.

Read more articles from this issue here.

Read more articles from the archives here.