Yinan Huang, Xue Gong, Yancheng Meng, Zhongwu Wang, Xiaosong Chen, Jie Li, Deyang Ji, Zhongming Wei, Liqiang Li* and Wenping Hu, Effectively Modulating Thermal Activated Charge Transport in Organic Semiconductors by Precisepotential Barrier Engineering, Nat. Commun. 2021, 12, 21-21. DOI:10.1038/s41467-020-20209-w

Abstract:

The temperature dependence of charge transport dramatically affects and even determines the properties and applications of organic semiconductors, but is challenging to effectively modulate. Here, we develop a strategy to circumvent this challenge through precisely tuning the effective height of the potential barrier of thegrain boundary (i.e., potential barrier engineering). This strategy shows that the charge transport exhibits strong temperature dependence when effective potential barrier height reaches maximum at agrain size near to twice the Debye length, and that larger or smaller grain sizes both reduce effective potential barrier height, rendering devices relatively thermostable. Significantly, through this strategy a traditional thermo-stable organic semiconductor (dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene, DNTT) achieves ahigh thermo-sensitivity (relative current change) of 155, which is far larger than what is expected from a standard thermally-activated carrier transport. As demonstrations, we show that thermo-sensitive OFETsperform as highly sensitive temperature sensors.