Furan is the simplest oxygen-containing five-membered heterocyclic compound. The furan ring has aromatic properties and can undergo various reactions such as halogenation, nitration, and sulfonation. The chemical structure is easy to modify. Heteroaromatics obtained by linking furan and benzene rings are important compounds for the preparation of organic devices. Among semiconductor materials, benzofuran derivatives have high solubility and easy processing properties. Moreover, the design of fused-ring furans utilizing benzofuran, naphthofuran, and anthrafuran can enhance the strength and luminescence of such materials. The introduction of oxo-heterocycles increases the ionization potential of these compounds and improves their environmental stability. The stability, rigidity, and light-emitting properties of benzofuran derivatives exhibit excellent carrier transport in organic field-effect transistors (OFETs) and light-emitting diodes (OLEDs), and exhibit excellent semiconducting properties.
Figure 1. Chemical structure of benzofuran
- Organic Light Emitting Diode (OLED): High-performance OLED light-emitting devices require various organic functional materials with good optoelectronic properties. For charge transport materials, good carrier mobility and high glass transition temperature are required. Benzofuran derivatives have high glass transition temperature, molecular thermal stability and suitable HOMO (Highest Occupied Molecular Orbital) energy level. By optimizing the device structure, the optoelectronic properties and lifetime of the OLED device can be effectively improved.
- Organic Field Effect Transistor (OFET): OFET is an active device in which organic semiconductor material is used as the carrier transport layer, and the conductivity of the material is adjusted by an electric field. The excellent transport properties of ambipolar semiconductor materials make them have important applications in the field of organic microelectronics. Benzofuran can be combined with benzothiazole and benzimidazole to design ambipolar semiconductor materials. Such materials have broad ultraviolet-visible-nearinfrared absorption spectra, good thermal stability, suitable frontier orbital energy levels, which are favorable for hole and electron injection, and can be used to fabricate air-stable bipolar field effect transistors.
- Daoliang Chen, Jie Li, Weimin Ma, Baolin Li, Yonggang Zhen, Xiaozhang Zhu, Wenping Hu, Hayato Tsuji, Eiichi Nakamura. 2, 7-Dioctylbenzofuro[3, 2-b]benzofuran: An Organic Semiconductor with Two-dimensional Transport Channels [J]. Asian J. Org. Chem., 2018, 7, 2228-2232.