Organic Field Effect Transistor (OFET) is a semiconductor device that uses π-conjugated organic compounds as semiconductor materials and uses the electric field effect of the control input loop to control the output loop current. OFET has broad application prospects in large-area manufacturing applications such as displays, solar cells, and portable electronic components such as flexible displays, electronic paper, radio frequency identification, and chemical sensors. As a key component of organic field-effect transistors, organic semiconductor materials directly determine the performance and stability of the device. During the operation of the OFET device, a conductive channel is formed on the interface of the insulating layer in the semiconductor layer, and the material in the conductive channel whose carriers are electrons is defined as an n-type organic semiconductor material. N-type organic semiconductor materials generally have a lower LUMO energy level, which facilitates the injection and stable transmission of electrons from the electrode. The introduction of electron withdrawing groups into organic compounds can effectively reduce the LUMO energy level of the molecule. Common electron withdrawing groups consist of halogen atoms (such as -F, -Cl), cyano groups (-CN), carbonyl groups and imide groups. The development of n-type semiconductor materials and p-type semiconductor materials is equally important. The organic complementary circuit constructed by the two has the advantages of low power consumption, fast operation speed, simple design, large noise tolerance, etc., and can be widely used in various digital logic circuits.
Figure 1. The chemical structure of some n-type organic semiconductors