Large-scale roll-to-roll printed, flexible and stable organic bulk heterojunction photodetector

Jianqiang Shen,Jia Sun,Huayan Xia,Si Xiao,Chujun Zhang,Jun He,Yongli Gao,Baoxing Liu,Chunhua Wang,Haipeng Xie,Yingping Zou,Jun Yuan,Junliang Yang,Sichao Tong

doi:10.1038/s41528-017-0020-y

Jianqiang Shen, Jia Sun + Show 12 more

Open Access

https://doi.org/10.1038/s41528-017-0020-y

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Abstract

A flexible and stable photodetector shows great potential applications in intelligent wearable devices, health monitoring, and biological sensing. The high-output fabrication of flexible and stable photodetector via the large-scale printing process would accelerate its commercialization. Herein, a high performance, flexible organic bulk heterojunction (BHJ) photodetector with good stability is designed and fabricated via a large-scale roll-to-roll (R2R) micro-gravure printing technique on polyethylene terephthalate (PET) or paper substrate, in which the organic BHJ active layer is structured with [6,6]-phenyl C61 butyric acid methyl ester (PCBM) and a donor–acceptor copolymer, i.e., employing 4,8-bis(2-ethylhexylthiophene) benzo[1,2-b;3,4-b′] dithiophene (BDTT) as the donor unit and 5,8-bis(5-thiophen-2-yl)-6,7-difluoro-2,3-bis(4-ethylhexyloxy-1-mata-luorophenyl) quinoxaline (ffQx) as the acceptor unit (PBDTT-ffQx). The PBDTT-ffQx/PCBM BHJ photodetector shows a broad photoresponse in ultraviolet and visible light, a high detectivity (D*) value up to 6.19 × 1011 Jones, and an excellent Iphoto/Idark as high as 5.6 × 102. It exhibits excellent flexibility and stability. Its performance parameters could maintain over 80% of original values after bending 10,000 cycles or exposing in ambient condition (humidity ~50%, temperature ~30 °C) for 50 days without any encapsulation. More importantly, the R2R micro-gravure printed PBDTT-ffQx/PCBM BHJ active layer is great homogeneous, and the responsivity (R) values of photodetector arrays show a very narrow distribution. The research results show that a high-performance PBDTT-ffQx/PCBM BHJ photodetector with well reliability and reproducibility can be fabricated via the R2R micro-gravure printing technique, which provides an available strategy for fabricating large-area and flexible electronic and optoelectronic devices.

Highlights

With the rapid development of chemical designs, all kinds of novel organic semiconductors with customized properties have been synthesized for optoelectronic devices,[8,9,10] and some conjugated polymers have been employed as the active materials in an organic photodetector, such as monoaniline-capped poly[(4,4′-bis(2-ethylhexyl)-dithieno[3,2-b:2′,3′-d] silole)-2,6-diyl-alt-(2,1,3-enzothiadiazole)-4,7-diyl] (PSBTBT-NH2) and a copolymer of 4,4-bis(2-ethylhexyl)-dithieno[3,2-b:2′,3′-d] silole and n-octylthieno[3,4-c]pyrrole-4,6-dione (PDTSTPD).[11,12,13]
The high-performance, flexible organic photodetector is designed with bulk heterjunction (BHJ) composed of PBDTT-ffQx and [6,6]-Phenyl C61 butyric acid methyl ester (PCBM), and fabricated by the large-scale, R2R micro-gravure printing technique on polyethylene terephthalate (PET) and paper substrate
The molecular structure of conjugated polymer PBDTT-ffQx is shown in Fig. 1a, which is constituted with a donor unit of BDTT and an acceptor unit of ffQx

Summary

ARTICLE OPEN

Large-scale roll-to-roll printed, flexible and stable organic bulk heterojunction photodetector. A high performance, flexible organic bulk heterojunction (BHJ) photodetector with good stability is designed and fabricated via a large-scale roll-to-roll (R2R) micro-gravure printing technique on polyethylene terephthalate (PET) or paper substrate, in which the organic BHJ active layer is structured with [6,6]-phenyl C61 butyric acid methyl ester (PCBM) and a donor–acceptor copolymer, i.e., employing 4,8-bis(2-ethylhexylthiophene) benzo[1,2-b;3,4-b′] dithiophene (BDTT) as the donor unit and 5,8-bis(5-thiophen-2-yl)-6,7-difluoro-2,3-bis(4-ethylhexyloxy-1-mata-luorophenyl) quinoxaline (ffQx) as the acceptor unit (PBDTT-ffQx). The PBDTT-ffQx/PCBM BHJ photodetector shows a broad photoresponse in ultraviolet and visible light, a high detectivity (D*) value up to 6.19 × 1011 Jones, and an excellent Iphoto/Idark as high as 5.6 × 102. The research results show that a high-performance PBDTT-ffQx/PCBM BHJ photodetector with well reliability and reproducibility can be fabricated via the R2R micro-gravure printing technique, which provides an available strategy for fabricating large-area and flexible electronic and optoelectronic devices

INTRODUCTION

Published in partnership with Nanjing Tech University

RESULTS AND DISCUSSION

Device fabrication

AUTHOR CONTRIBUTIONS

ADDITIONAL INFORMATION