CFM Lunch Seminar

The October speaker is Dr Katelyn Goetz from NIST.  The title of the talk will be: “Using and Measuring Excitons for Novel Organic Optoelectronic Devices”.

This is our monthly CFM Seminar and lunch will be provided in the Olin 105 beginning at 12:30 pm, followed by the speaker at 1:00 pm.  Abstract is below.

Measuring the Properties of Singlet Fission by Using Transistors

Katelyn P. Goetz

Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD 20899

Excitons are a quasiparticle consisting of an electron and hole bound by the electrostatic Coulomb force. They are formed in materials upon the absorption of a photon with higher energy than the bandgap and are thus an intermediate state in the conversion of light to charge and vice versa. In organic semiconductors, they have a particularly high binding energy. While this property can reduce the efficiency of devices like photovoltaic and light-emitting diodes, its stability in organic semiconductors makes it attractive for novel technologies. This is the focus of our growing excitonics initiative at NIST.  For example, we have recently demonstrated a magnetic-field sensor based on an organic light-emitting diode and an organic photovoltaic diode. As a part of advancing this technological effort, we are also investigating the measurement and characterization of the exciton. Properties are often characterized on the ultrafast timescale by using advanced spectroscopic techniques. However, potential device applications raise the need to develop measurements to understand exciton dynamics on a slower, operationally relevant timescale.