In organic field effect transistor materials, organic semiconductors play a very important role. Ambipolar organic semiconductors are a special type of organic semiconductor materials that can transport both electrons and holes under certain conditions by changing the gate voltage. Therefore, when ambipolar materials are used to construct complex circuits, there is no need to separately deposit two materials of p-type and n-type, which can greatly simplify the device preparation process, improve efficiency, and reduce costs. This is of great significance to the construction of organic P/N junction logic complementary circuits. Generally speaking, ambipolar materials have a narrow band gap (<1.5eV), so that holes and electrons can be injected at the same time. Therefore, ambipolar semiconductors are generally small molecules or polymers with D-A structure.
Figure 1. Representative ambipolar semiconductor materials
- Electrolytic capacitor: Utilizing the conductivity characteristics of the ambipolar OFET, it is combined with the electrolytic capacitor to form a bipolar semiconductor electrolytic capacitor, which can work on alternating current. The electrolytic capacitor not only overcomes the shortcomings of large loss and short working time, but also replaces the existing ordinary capacitors in some occasions, saves a lot of raw materials, and further broadens the application field of electrolytic capacitors.
- Semiconductor laser: Semiconductor lasers (LD) have the advantages of small size, long life, high efficiency, etc., and are widely used in various fields such as communications, laser ranging, lidar, automatic control, and detection instruments. Using ambipolar semiconductors in LD can realize a bidirectional temperature control system. Through the direction and magnitude of the driving current, heating or cooling of the LD is realized. Make it work in a constant temperature state within an ambient temperature range of 0°C-40°C. Broaden the LD operating temperature range, ensure the life of the laser, and enhance the reliability and stability of the laser system.
- Inverter: Inverter is a converter that can convert DC power (battery, storage battery) into AC power with constant frequency and voltage or with frequency and voltage regulation. Ambipolar OFETs have very important applications in inverters, and there is no need for a multi-step deposition process in the manufacturing process, and it has the advantages of flexibility, low cost, and light weight.
- Francisco Otón,Raphael Pfattner,Egon Pavlica,Yoann Olivier,Evelyn Moreno,Joaquim Puigdollers,Gvido Bratina,Jérôme Cornil,Xavier Fontrodona,Marta Mas-Torrent,Jaume Veciana,Concepció Rovira. Electron-Withdrawing Substituted Tetrathiafulvalenes as Ambipolar Semiconductors [J]. Chem. Mater. 2011, 23, 3, 851–861.