Excellent electrical conductivity when doped with hydrogen chloride
[투데이에너지 송명규 기자] ‘Inductive conductor’ is an electronic material suitable for display or wearable electronic devices. However, its use was limited due to its low charge mobility. Recently, a study that raised the charge mobility to the highest reported value has been drawing attention.
UNIST (President Yong-Hoon Lee), Department of Energy and Chemical Engineering Professor Jong-Bum Baek’s team succeeded in synthesizing’C5N (C5N) two-dimensional organic polymer structure’ through aromatic cyclization reaction. When this organic polymer structure was made in the form of a thin film and used in a semiconductor transistor device (FET), charge mobility was increased by several tens of times. In addition, when the structure is doped with hydrogen chloride (HCl), the electrical conductivity is also greatly increased, so that it can be used as a conductive material.
The research team reacted two kinds of chemicals (HAB and PTK) to obtain a C5N (C5N) structure. Unlike graphene, which forms a hexagonal ring only with carbon (C), this structure has excellent charge mobility because uniform pores and nitrogen atoms (N) are added to the two-dimensional structure. This is the highest value among organic semiconductor charge mobility ever reported. Charge mobility is a fast movement of electrons or holes inside a material, and when a semiconductor device is made of a material with low charge mobility, electrical signal transmission is slowed down and problems such as color conversion delay appear in displays.
The ring structure of the developed two-dimensional material is a structure obtained through an’aromatic cyclization reaction’, so it is very stable and can withstand high temperatures of 600°C.
Dr. Javeed Mahmood, the first child, explained, “All parts of the structure are made of a ring shape, which improves chemical and thermal stability compared to the existing two-dimensional organic structures.” .
In addition, this structure has better electrical conductivity than the existing conductive polymer chain polyaniline, and when doping with hydrogen chloride (HCl), the conductivity is improved by more than 140 times (1038 S/cm) and can be used as a versatile conductive polymer. I can.
Organic semiconductors have been actively studied in recent decades as materials to replace inorganic silicon semiconductors because of their various advantages such as flexibility and lightness, low process cost, and ease of physical property control. However, most organic semiconductors have difficulty in replacing inorganic semiconductor materials due to the charge mobility that falls short of expectations.
Prof. Jong-beom Baek, who is in charge of this research, said, “With this research, we have overcome the inherent problem of using 2D polymers as organic semiconductor materials, which is the low charge mobility.” He said.
The research, together with the research team at Seoul National University (President Se-Jung Oh), Professor Jun-Hak Oh of the Department of Chemical and Biological Engineering, was published on the 20th in the renowned international journal Advanced Materials. The research was carried out with the support of the Ministry of Science and ICT’s Leader Researcher Support Program (Creative Research), the BK21 Plus Project, the Center for Excellent Science Research (SRC), and the UK Brand Promotion Project (UNIST).
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