Evaluation of hole mobility in non-peripherally alkyl-substituted tetrabenzotriazaporphyrin thin films by MIS-CELIV method

Abstract

Charge carrier mobility measurement of donor materials for organic thin-film solar cells, 1,4,8,11,15,18,22,25-octaalkyltetrabenzotriazaporphyrin (CnTBTAPH₂), was carried out by using metal-insulator-semiconductor charge carrier extraction by linearly increasing voltage (MIS-CELIV) method. The estimated carrier mobility, which is based on the hopping conduction process between the molecular columns composed with CnTBTAPH₂, sequentially decreased depending on the alkyl-chain length. The alkyl-chain length dependence of the mobility was discussed by taking the evaluated activation energy and the inter-column spacing into consideration.

Keywords:

• Hybrid macrocycle
• porphyrin
• phthalocyanine
• tetrabenzotriazaporphyrin
• organic semiconductor
• carrier mobility measurement

Additional information

Funding

This work was partially supported by the JSPS KAKENHI Grant Numbers 20H04672, 20H00391, 19K21975, and by the JSPS Core-to-Core Program A., Advanced Research Networks.