图片1.png

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)

微信图片_20220823145854.jpg
Graph2.tif
Graph21.tif

Degradation: Evolution of defects

Sensitive External Quantum Efficiency (S-EQE)

图片4.png
0aa36c24-e710-4a75-a485-bd12361e54bf.PNG
图片3.png

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)

图片6.png
图片5.png

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.