Colors of Life and Optoelectronics: Zinc Porphyrins for Light-Emitting Electrochemical Cells and Organic Photodetectors
Doktorsavhandling, 2020

The field of organic optoelectronics constitutes an interdisciplinary field that covers chemistry, physics, materials science and biology. The technological promises of the organic materials over their inorganic counterparts include a lower production cost and the feasibility to be processed through solution-based techniques on large-area and/or flexible substrates. Among organic optoelectronic devices, two technologies are discussed in this thesis. Those are light emitting electrochemical cells (LECs) and photomultiplication (PM) type organic photodetectors (OPDs). The LEC is a light emitting technology that has attracted a lot of scientific interest due to its simple device architecture and fabrication. A category of LECs that is of high interest, are those LECs consisting of materials emitting near-infrared (NIR) light. This specific field is highly alluring, due to the unique applications NIR light can generate in a wide range of fields from medicine to optical communications. However, organic NIR emitters are inherently of lower efficiency when compared to other wavelengths, thus posing a challenge in material design. Hereof, an attempt was made in the context of this work to design and synthesize emitters that will produce light in the deep NIR region and in a functional LEC. The problem of high aggregation of NIR emitters was tackled by blending with appropriate host materials. On the other side, PM type OPDs aim in sensing and not in the production of light. The characteristic of this special category of OPDs is the possibility of enhancing the received weak signal without the need of external components in the device, like photomultiplier tubes. However, since this specific field is not mature yet, there is not adequate knowledge in material design. Thus, there is a need in discovering the materials that will lead to photomultiplication enabling the construction of more efficient devices in the future. In order to achieve all the accomplishments that will be discussed in this thesis, there was a category of molecules that was the heart of all studies. These molecules, often called as colors of life, due to their importance in many processes occurring in nature were porphyrins. Porphyrins are highly versatile motifs and were the tools that led both into production of deep NIR light but also into improving the detection of weak light.

photomultiplication

aggregation

light emitting electrochemical cell

porphyrins

optoelectronics

near-infrared

10:an, Kemigården 4
Opponent: Rubén D. Costa, Technical University of Munich

Författare

Mariza Mone

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Ergang Wang Group

Low-gap zinc porphyrin as an efficient dopant for photomultiplication type photodetectors

Chemical Communications,; Vol. 56(2020)p. 12769-12772

Artikel i vetenskaplig tidskrift

Star-Shaped Diketopyrrolopyrrole-Zinc Porphyrin that Delivers 900 nm Emission in Light-Emitting Electrochemical Cells

Chemistry of Materials,; Vol. 31(2019)p. 9721-9728

Artikel i vetenskaplig tidskrift

Mariza Mone, Shi Tang, Zewdneh Genene, Petri Murto, Martyn Jevric, Joan Ràfols-Ribé, Birhan A. Abdulahi, Jia Wang, Wendimagegn Mammo, Mats R. Andersson, Ludvig Edman and Ergang Wang. Near-Infrared Emission by Tuned Aggregation of a Porphyrin Compound in a Host-Guest Light-Emitting Electrochemical Cell

The field of organic electronics is one of the most fast-growing fields in material science. This special category of electronics refers to those electronic devices where the active materials are based on compounds consisting of carbon. Those can be either polymers or small molecules. The reason why those materials are extremely interesting is due to their special characteristics. Τhey are mechanically flexible, lightweight while their properties are easily tunable. These attributes are not easily achievable by their inorganic counterparts. In the field of organic electronics everything starts from chemistry, as it was also the case for this dissertation. More specifically, small molecules based on the porphyrin motif were designed in order to produce near-infrared (NIR) light. NIR light is very interesting due to the unique applications it can find in fields like medicine, biometrics and optical communications. The materials synthesized here, were then characterized and light emitting devices were fabricated. However, these were not the only constructs studied. Devises able to sense light, known as photodetectors, are also presented. The special design of the photodetector construct described in this work aims in multiplying their efficiency and thus improving their ability to detect even very at very low light conditions.

Drivkrafter

Hållbar utveckling

Ämneskategorier

Kemi

Styrkeområden

Materialvetenskap

ISBN

978-91-7905-401-4

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4868

Utgivare

Chalmers tekniska högskola

10:an, Kemigården 4

Online

Opponent: Rubén D. Costa, Technical University of Munich

Mer information

Senast uppdaterat

2020-11-29