2,7-Diphenyl[1]benzoselenopheno[3,2-b][1]benzoselenophene as a Stable Organic Semiconductor for a High-Performance Field-Effect Transistor

Abstract

[1]Benzoselenopheno[3,2-b][1]benzoselenophene (BSBS) and its 2,7-diphenyl derivative (DPh-BSBS) were readily synthesized from diphenylacetylene and bis(biphenyl-4-yl)acetylene, respectively, with a newly developed straightforward selenocyclization protocol. In contrast to the parent BSBS that has poor film-forming properties, the diphenyl derivative DPh-BSBS formed a good thin film on the Si/SiO(2) substrate by vapor deposition. X-ray diffraction examination revealed that this film consists of highly ordered molecules that are nearly perpendicular to the substrate, making it suitable for use in the fabrication of organic field-effect transistors (OFETs). When fabricated at different substrate temperatures (room temperature, 60 degrees C, and 100 degrees C) in a "top-contact" configuration, all the DPh-BSBS-based OFET devices exhibited excellent p-channel field-effect properties with hole mobilities >0.1 cm(2) V(-1) s(-1) and current on/off ratios of approximately 10(6). This high performance was essentially maintained over 3000 continuous scans between V(g) = +20 and -100 V and reproduced even after storage under ambient laboratory conditions for at least one year.

Thienoacene‐Based Organic Semiconductors

“…[ 85 ] Although its alkyl derivatives [ 86 ] and ester derivatives with long alkyl groups [ 87 ] have been focused on as liquid crystalline materials, the application of BTBT derivatives to OFETs had not been examined until recently, and the fi rst OFET based on diphenyl derivatives of [1]benzoselenopheno [3,2-b ] benzoselenophene (DPh-BSBS, 33f ) was reported in 2006. [ 88 ] Thereafter, air-stable p-channel OFETs with mobilities higher than 1.0 cm 2 V − 1 s − 1 were reported using diphenyl (DPh-BTBT, 33b ) [ 89 ] or dialkyl derivatives of BTBT ( 33c ). [ 90 ] [ 14 ] with six fused aromatic rings and its dodecyl derivative ( 4c ) [ 91 ] were developed as stable π -extended organic semiconductors that can afford OFETs with mobilities that are as high as 7.9 cm 2 V − 1 s − 1 for vapor-deposited thin fi lms and 11 cm 2 V − 1 s − 1 for solution-processed single-crystalline fi lms.…”

An Ultra Closely π‐Stacked Organic Semiconductor for High Performance Field‐Effect Transistors

“…However, there remain some key challenges in this field,namely the mobility (most OFETs with a mobility lower than 1 cm 2 V -1 s -1 ), on/off ratio and environmental stability. [2,3] Moreover, quantum mechanical calculations [4,5] and structural analysis [6] have predicted that high mobility can be obtained when conjugated molecules have strong interactions with neighboring molecules to maximize the overlap of p molecular orbits. Hence, theoretically speaking, a p stacked structure is expected to provide more efficient orbital overlap and thereby facilitates carrier transport.…”

Organic π‐Conjugated Molecules for Organic Semiconductors and Photovoltaic Materials

“…Detailed studies of the physicochemical properties of the heterocycles 26 and 27 reveal the perturbation effect of fused benzene rings on the electronic structure, suggesting that the control of the HOMO level can be regarded as a key factor for the stabilization of p-channel organic semiconductors in OFET applications [49]. Compounds 28 and 29 have proven the utility of fused chalcogenophene compounds as high-performance OFET materials [50,51]. It should be noted that OFETs based on the selenophene analog 29 showed high stability both in the shelf lifetime test and in the operation lifetime test in air, indicating that 29 is a valuable OFET material possessing both high performance and stability [50].…”

“…Compounds 28 and 29 have proven the utility of fused chalcogenophene compounds as high-performance OFET materials [50,51]. It should be noted that OFETs based on the selenophene analog 29 showed high stability both in the shelf lifetime test and in the operation lifetime test in air, indicating that 29 is a valuable OFET material possessing both high performance and stability [50]. Figure 20.5) is an analog of pentacene that possesses a similar rigid, linear, and coplanar conjugated structure [52].…”