Research Areas
Organic Solar Cells
Photovoltaics is the process of converting sunlight directly into electricity using solar cells. Today it is a rapidly growing and increasingly important renewable alternative to conventional fossil fuel electricity generation, but compared to other electricity generating technologies, it is a relative newcomer, with the first practical photovoltaic devices demonstrated in the 1950s.
The fabrication of Organic Solar Cell is shown in the picture. In our lab, we synthesize polymers to incorporate them as an active layer in Organic Solar Cells. These polymers are characterized by various techniques.
Conjugated Polymers
Conjugated polymers are, at their very basic level, polymeric materials which have delocalized electron density along their backbone repeat structure. Most often this arises from structures containing alternating C-C σ- and π-bonds. Photovoltaics and OLEDs are one application where conjugated polymers are pushing towards practical applications in real world devices. The properties of conjugated polymer systems depend on their repeat structure, i.e. the atomistic arrangement of the monomer units within the chain, and the morphology of the chains, i.e how they are arranged and packed together.
Suitable materials for each potential application (light emitting diodes, solar cells, etc) can only be obtained then by controlling both the chemical repeat structure and the morphology of the polymers. Research efforts focus on designing molecular structures to optimize properties such as band-gap, mobility, and processability, as well as controlling the morphology of the chains for each specific application of conjugated polymers.
Organic Light Emitting Diodes
In our laboratory, we design, synthesize, and characterize organic materials for organic light-emitting diodes (OLEDs), which are electroluminescent devices that generate light through the radiative recombination of electrically injected charge carriers within organic semiconductors. OLEDs consist of thin organic layers positioned between electrodes, where electron–hole recombination leads to light emission with high color purity and efficiency.
Our research encompasses the development of molecular and polymeric emissive materials and optimized device architectures aimed at achieving high efficiency, long operational stability, and controlled emission characteristics. By integrating materials chemistry, photophysical characterization, and device fabrication, we establish structure–property–performance relationships that support the advancement of OLED technologies for display, solid-state lighting, and emerging optoelectronic applications.
TADF Materials
Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes (TADF OLEDs) are a class of organic optoelectronic devices that achieve high electroluminescence efficiency through the utilization of both singlet and triplet excitons. In TADF materials, a small energy gap between the lowest singlet excited state (S₁) and the lowest triplet excited state (T₁) enables efficient reverse intersystem crossing (RISC), allowing non-emissive triplet excitons to be thermally up-converted into emissive singlet states. As a result, TADF OLEDs can theoretically reach internal quantum efficiencies of up to 100% without relying on heavy-metal phosphorescent emitters.
By eliminating the need for rare and costly metals such as iridium or platinum, TADF OLEDs offer a more sustainable and versatile approach to high-efficiency light emission. These devices are compatible with both vacuum-deposited and solution-processed fabrication techniques, making them attractive for large-area, flexible, and low-cost display and lighting applications. Owing to their tunable emission colors, high efficiency, and material design flexibility, TADF OLEDs have emerged as a key technology in next-generation organic light-emitting systems.
In our laboratory, we design, synthesize, and characterize advanced organic materials for thermally activated delayed fluorescence (TADF) organic light-emitting diodes. Through an interdisciplinary approach that integrates synthetic chemistry, photophysics, and device engineering, we develop efficient and environmentally sustainable light-emitting materials.
Polymer Morphologies
Polymers are promising class for electroluminescence (EL) devices due to their ease of preparation, versatility and tunable band gap. An important part of our research is to study how the material properties affect devices performance, and to model device performance under various operation conditions which will provide insight into synthesis of new materials and optimization of device structure for further improvement in device performance.