Research Project

Time-domain impedance analysis of carrier recombination in ZnO thin films and quantum dot-in-metal nanogapstructures

It is known that zinc oxide exhibits unique properties, which make it interesting for study and numerous applications. The presence of SiOx native oxide and defects at the ZnO/Si interface affects the charge carrier generation and recombination and drastically changes the electrical and photoelectric properties of the heterojunction. We intend to approximate the surface photovoltage non-exponential decays captured in nm-sized ZnO films by the equivalent RC circuit model. Our aim is to optimize the equivalent circuit and to reproduce the measured decays rather well.

Another important point is related to the influence of Au plasmonics on time-varying photocurrent generation in integrated thiol-linked CdSe quantum dot/Au nanogap structures.The plasmonic absorption is sensed utilizing thermoacoustic detection technique. Due to rapid energy transfer from the dot to closely spaced Au surface through thiol links, a smooth transmission channel of electrons is established that forms a detectable photocurrent, which can be tuned by a bias voltage. These plasmonic nanogap structures enable numerous photocatalytic applications including sensing, photodetection, and solar energy conversion.

First stay: 6th July to 6th August 2022
Second stay: 10th December 2022 to 21st January 2023
Third stay: 29th April to 1st June 2023