Merranda Schmid
Speaker's Institution
Colorado State University
4:00 PM
Chemistry A101
Mixer Time
3:45 PM
Mixer Time
Chemistry B101E
Calendar (ICS) Event
Additional Information

Literature Seminar

Transition metal dichalcogenides (TMDs), due to their unique optoelectrical properties, have been studied for decades. These van der Waals semiconductors are stable under electrochemical conditions while having a desirable band gap suitable for absorbing a wide range of solar wavelengths without wasting much energy as seen in solar energy conversion devices. Mechanical exfoliation of these materials yielding ultrathin thickness has prompted a renewed interest in recent years. Of course, there are still fundamental questions being asked about their (photo)electrochemical behavior. Recent studies have shown that ensemble measurements are not an accurate representation of their observed behavior. More specifically, structure-function relationships are being investigated on individual nanoflakes. Scanning electrochemical cell microscopy (SECCM) is a recently developed technique that allows for single nanoflake measurements that would otherwise be hidden in ensemble measurements. Because of its configuration, SECCM allows for simultaneous topographical and electrochemical measurements at nanoscale resolution with fast sampling rates. Hill et al. uses this technique to study the effect of step/edge height on the photocurrent in an inner and outer sphere redox couple. Their findings support that step/edge height determines whether they are beneficial or detrimental to charge carrier generation and collection. Additional modeling shows the effect of basal plane thickness on photocurrent based on simulations with potential profiles within the materials.

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