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Welcome to the TSANG group
Our group is focused on developing solution processed electronic devices and advanced characterization technique on the electronic processes in organic and nano materials.
Photoluminescence (PL) signal of a material provides information on the chemical composition, energy bandgap, recombination, and defects . During the crystallization and film formation of perovskite or organic materials, in-situ PL provides direct information on the optoelectronic properties of the out-of-equilibrium phase, and helps in understanding crystallization and film formation kinetics. It helps to bring insight into developing novel high performance materials.
Crystallization and film formation dynamics
In-situ Photoluminescence (PL)
Degradation: Evolution of defects
Sensitive External Quantum Efficiency (S-EQE)
We have developed a highly sensitive external in-situ quantum efficiency (s-EQE) technique with a dynamic range of 10E9 (from 100% to 10E-7%). Such high sensitivity is capable to measure the photocurrent generated by excitation the defect stats in mid-gaps. This in-situ technique helps to understand the evolution of defect states under different operation conditions, and provides insight to further stabilize the materials for long-term applications.
Excitonic Properties of Materials
Electroabsorption (EA)
Electromodulation (EM) spectroscopy, a powerful technique to monitor the changes in polarizability p and dipole moment u of materials upon photo-excitation, can bring direct insight into the excitonic properties of materials. It is an interesting technique to reveal the excitonic effect from molecular packing, donor-acceptor interaction, particular in the charge transfer processes in light emitting and photovoltaic materials.
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