A research team of Energy Science and Engineering at DGIST has developed a technology to produce environment friendly water-borne semiconductor inks, using surfactants which are additives that mix substances of different properties and a component of soap.

       Polymer semiconductors are carbon compounds showing the electrical properties of semiconductors. It has been highlighted as a next-generation material of wearable smart devices etc. not only because they are flexible and light in weight, but also they can be processed in a wide area at low cost through the solution process. However, there is an issue that it causes significant environmental pollution as toxic organic solvents are used in the process.

       Despite the limitations, the research team has developed a semiconductor surface control technique using surfactants for environment friendly semiconductor manufacturing processes that do not use toxic organic solvents and has produced water-borne semiconductor inks.

       In the study, the newly developed waterborne semiconductor ink by the research team has small colloidal particles and less surfactant micelles compared to the waterborne semiconductor inks in the previous studies. As a result, it has a relatively flat surface than the conventional waterborne semiconductor inks. The black and white image in the figure shows the comparison of the surface of the thin film made with the waterborne semiconductor ink developed in this study and conventional one. According to the research team, the technique is expected to be applied in various electronic devices such as P-type and N-type transistors as well as PN diodes, complementary inverters, photodiodes as high-quality thin films.

       Professor Chung, author of the study stressed the significance by stating that his research has fundamentally solved the environmental pollution problem generated during the production of organic semiconductor, which is spotlighted as the core material of wearable electronic devices. They have the technology that can disperse various semiconductor materials into water through the simple chemical modification. They expect that it can be used in various optoelectronic devices ranging from transistors to solar cell, composite circuit, and image sensor.

Fig. Comparison of the waterborne semiconductor ink of this study and that of the previous studies.

(Image credit: Daegu Gyeongbuk Institute of Science and Technology (DGIST))

Source: www.sciencedaily.com