Quantitative analysis of the density of states distribution in N-type polymer filed-effect transistor

In the advancement of polymer field-effect transistors, both p-type and n-type polymer transistors are indispensable because they are the basic components of complementary metal oxide semiconductor (CMOS) logic circuitry. The scarcity of research on the interface properties of n-type polymer transistors, particularly regarding their density of state (DOS) distribution hinders the device modeling and further optimization of n-type polymer transistor. Consequently, the focus on understanding and investigating n-type polymer transistors interface properties holds substantial value and relevance, as it fills a critical knowledge gap in the polymer transistors. In view of this, an n-type poly((N,N0-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-5,50-(2,29-bisthiophene)) (N2200) polymer transistor was fabricated and a dynamic quantitative measurement method was utilized to investigate the DOS distribution of polymer transistors. Comparative analyses were conducted on the drain current (ID), carrier charge (Q), and DOS with varying pulse fall times (Tf). Variations in pulse fall times revealed significant differences in the DOS near the edge of the lowest unoccupied molecular orbital (LUMO), with a maximum DOS of 8 × 1013 cm−2 eV−1 observed at Tf = 1000 μs and a maximum of 2 × 1013 cm−2 eV−1 at Tf = 100 μs. By using different Tf, an effective method was successfully utilized for analyzing the effects of water and oxygen molecules on the DOS distribution of n-type polymer transistors. [Display omitted]