Controlled Filling of Donner and Accepter Molecules inside SWCNTs for Precise Carrier Density Control

摘要

We are applying single-wall carbon nanotube (SWCNT) thin films for electric power generation by moving electrolyte droplet on them. To maximize the efficiency of the power generation, carrier density of SWCNTs has to be precisely controlled. In this study, we contribute the precise control of the amount of electron donner and accepter molecules inside SWCNTs by encapsulating organic molecules . We selected N,N’-bis(3-pentyl)perylene-3,4,9,10-bis(dicarboximide) (PBI) and 2,4-bis[4-(N,N-diphenylamino)-2,6-dihydroxyphenyl]squaraine (DPSQ) as donner and accepter molecules, respectively. Coronene was used as the dummy molecules which do not affect the carrier density of SWCNTs. After adjusting the concentration ratio of PBI (or DPSQ) to coronene in a common solvent 1,4-dioxane, the solution was refluxed with dispersed SWCNTs (EC1.5, Meijo Nano Carbon, unsorted). After careful washing process, we prepared several SWCNTs with different ratio of dopant molecules to coronene. Figure 1 shows the optical absorbance of dopant molecules inside SWCNTs as a function of dopant molecule ratio in the mixture of dopant and coronene molecules. The curves of PBI and DPSQ in Fig. 1 show a similar increment, indicating that the controlled filling is successful. This controllability is realized by the dummy molecules which are co-filled in a prepared ratio with similar filling probability to the dopant molecules. We will talk about the latest results in this presentation.