HIGASHIHARA laboratory

Research fields/Keywords:synthesis of π-conjugated polymers, precision polymerization, organic thin film solar cells, semiconducting block copolymers, semiconducting elastomers, freshness-retaining package

Location:Building No. 10, 4th floor, room 404
Laboratory Website:https://higashihara-lab.yz.yamagata-u.ac.jp/
Laboratory Introduction:PDF(1.6MB)

Professor Tomoya HIGASHIHARA

At present, 2nd year Ph.D.: 2, 2nd year Masters: 1, 1st year Masters: 2, Bachelors: 4 students

(1) Precise synthesis of semiconducting polymers using zincate complex and dialkyl zinc

Poly(3-hexylthiophene) (P3HT) has attracted great attention as a model polymer for use in organic electronics. Polymerization with the conventional Grignard monomer allows for sophisticated control of molecular weight, molecular weight distribution and regioregularity. However, if highly reactive Grignard reagents are employed, side reactions and solvent purification become problematic. We found that using zincate complexes with large steric hindrance and low nucleophilicity enabled the polymerization to proceed efficiently in the presence of water or in the atmosphere (ACS Macro Lett. 2012). Recently, we have also succeeded in the synthesis of P3HT with extremely narrow molecular weight distribution (PDI = 1.03) (JPSA 2014).

(2) Increasing power conversion efficiency and durability of thin film organic solar cells using semiconducting block copolymers

It is essential to develop methods to control the phase separated structure of blends of p-type and n-type semiconductors in the thin films used in bulk heterojunction organic solar cells. Investigating the principle behind the addition of semiconducting block copolymers to blends, we found that ABA triblock copolymers were more effective compatibilizers than AB diblock copolymers. This suggests that differences in the block sequence are related to the specific characteristics of electronic devices (ACS Appl. & Interfaces 2016).

(3) Development of thermoplastic semiconductor elastomers

We have clarified that ABA triblock copolymers consisting of hard-soft-hard segments (A=P3HT, B=soft polymer) are semiconducting elastomeric polymers, withstanding elongations greater than 300% (presented at the 65th SPSJ Annual Meeting).

(4) Development of freshness-retaining package systems using hydrogels

We are collaborating with the faculty of agriculture and the faculty of science for the development of freshness-retaining package systems. We have begun a trial export of Yamagata brand cherries since June 2016.