Synthesis of the extended phenacene molecules, [10]phenacene and [11]phenacene, and their performance in a field-effect transistor

Hideki Okamoto,Chia-Wei Chou,Yen-Fa Liao,Shino Hamao,Yasuhiro Takabayashi,Hisako Sugino,Ritsuko Eguchi,Yoshihiro Kubozono,Shin Gohda,Luo Uei Liang,Hidenori Goto,Hirofumi Ishii,Paul Yu-Hsiang Yen,Germar Hoffmann

doi:10.1038/s41598-019-39899-4

Abstract

The [10]phenacene and [11]phenacene molecules have been synthesized using a simple repetition of Wittig reactions followed by photocyclization. Sufficient amounts of [10]phenacene and [11]phenacene were obtained, and thin-film FETs using these molecules have been fabricated with SiO2 and ionic liquid gate dielectrics. These FETs operated in p-channel. The averaged measurements of field-effect mobility, <μ>, were 3.1(7) × 10−2 and 1.11(4) × 10−1 cm2 V−1 s−1, respectively, for [10]phenacene and [11]phenacene thin-film FETs with SiO2 gate dielectrics. Furthermore, [10]phenacene and [11]phenacene thin-film electric-double-layer (EDL) FETs with ionic liquid showed low-voltage p-channel FET properties, with <μ> values of 3(1) and 1(1) cm2 V−1 s−1, respectively. This study also discusses the future utility of the extremely extended π-network molecules [10]phenacene and [11]phenacene as the active layer of FET devices, based on the experimental results obtained.

Highlights

IntroductionSufficient amounts of [10]phenacene and [11]phenacene were obtained, and thin-film field-effect transistors (FETs) using these molecules have been fabricated with SiO2 and ionic liquid gate dielectrics
The key step for synthesizing large phenacene molecules is based on the photocyclization of diarylethene29–35, known as the Mallory photocyclization, followed by oxidative aromatization to form a phenanthrene-like zigzag benzene array
The diarylethene 5 was used in the Mallory photocyclization without separation of E- and Z-isomers; the crude diarylethene 5 was photolyzed at 365 nm in o-dichlorobenzene at ca. 150 °C in the presence www.nature.com/scientificreports of a catalytic amount of I2 to produce [10]phenacene as an off-white precipitate, which was collected by filtration. [11]Phenacene was prepared by a Wittig reaction between bis-phosphonium salt 8 and phenanthrenecarbaldehyde 9, followed by a two-fold Mallory photocyclization of the resulting diene 10 in boiling o-dichlorobenzene

Summary

Introduction

Sufficient amounts of [10]phenacene and [11]phenacene were obtained, and thin-film FETs using these molecules have been fabricated with SiO2 and ionic liquid gate dielectrics. Our study of the fabrication and characterization of FETs using phenacene molecules, which consist of coplanar fused benzene rings in a repeating W-shaped pattern, has demonstrated excellent FET properties. Our study of the fabrication and characterization of FETs using phenacene molecules, which consist of coplanar fused benzene rings in a repeating W-shaped pattern, has demonstrated excellent FET properties19,23,26–28 This high performance is due to the strong π-π interaction between phenacene molecules enabled by the extension of the benzene network. The structural/electronic parameters of [10]phenacene and [11]phenacene, as well as their FET parameters, have been fully compared with those of other phenacene molecules, and the future prospect for FET application of extremely extended phenacene molecules is discussed

Methods

Results

Conclusion