Zhu lab: Solar Energy Conversion & Other Interface Problems

Post-doc openings:

(a) Protein activity on polymer nanopatterns (joint with Tim Lodge)

(b) Exciton dynamics in organic photovoltaic.

(c) Exciton dissociation from quantum dots.

One of the key questions we are focusing on is at the heart of future photovoltaic technology: How can one extract electrons and holes from excitons in organic semiconductors or inorganic quantum dots? To anwser this question, we use state-of-the-art laser spectroscopic techniques, in combination with model interfaces for organic and quantum dot solar cells. These techniques include femtosecond time-resolved two-photon photoemission spectroscopy (2PPE) and second harmonic generation (SHG). As examples, recent discoveries in our lab showed for the first time how an electron and a hole is bound by the Coulomb potential across an organic semiconductor (pentacene) interface and how one can extract hot electrons from a photoexcited PdSe quantum dot.

In addition to photovoltaic, we are also interested in a variety of interfacial problems related to organic semiconductor technology, bio-interfaces, and biotechnology. As examples, we apply in situ FTIR-NIR spectroscopy to operating organic thin film transistors or solar cells to quantify charge carriers. We design optimal surfaces for protein and cell membrane microarrays using novel surface chemistry. We also probe the nanomechanics of soft interfaces, such as interfacial water and the cell membrane.