Flexible All-Organic Photorefractive Devices

Abstract

The objective of the present study is to demonstrate and evaluate the photorefractive (PR) performance of an all-organic PR device with a self-assembled monolayer (SAM)-modified organic conductive electrode of PEDOT:PSS coated on polyethylene terephthalate (PET). The PR composite consisted of a triphenylamine-based photoconductive polymer: poly(4-(diphenylamino)benzyl acrylate) (PDAA), a triphenylamine photoconductive plasticizer: (4-(diphenylamino)phenyl)methanol (TPAOH), a nonlinear optical dye based on aminocyanostyrene: (4asacycloheptylbenzylidenemalononitrile) (7-DCST), and soluble fullerene: [6,6]-phenyl C 61 butyric acid-methyl ester (PCBM). For comparison with the all-organic PR device, the PR performances using PET/ITO, glass/ITO, and glass/PEDOT:PSS substrates were also evaluated. At an applied electric field of 40 V μm −1 , the diffraction efficiency and the response time of the PR device using the PET/PEDOT:PSS-SAM substrate were 21.9%, and 390 ms, respectively. As a result of repeating bending tests on this all-organic PR device, we found that the flexible PR device with the PET/PEDOT:PSS-SAM substrate had a potential to withstand bending 10 000 times and that the change in the haze value strongly influenced the degradation of PR performance.

Photorefractive Response Enhancement in Poly(triarylamine)-Based Polymer Composites by a Second Electron Trap Chromophore

“… 13 , 16 , 19 − 23 Furthermore, the flexibility of the photorefractive films has an advantage of application in flexible devices. 24 …”

“…13,16,19−23 Furthermore, the flexibility of the photorefractive films has an advantage of application in flexible devices. 24 Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) with high hole mobility of 10 −2 −10 −3 cm 2 V −1 s −1 was developed in the electrophotonic field of organic transistors and organic solar cells. Due to high hole mobility, PTAA PR composites are expected to have faster response PR composites with high optical diffraction, but they also exhibit extremely large dark currents even though a relatively low electric field is applied, which induces a high risk of dielectric breakdown.…”

“…Since photorefractive (PR) polymers were first investigated in 1991, many studies have been reported to investigate and develop photorefractive polymers. − The essence of photorefractive polymers is the high optical diffraction efficiency and large optical gain based on the Pockels effect and molecular orientation of nonlinear optical dyes under the bias of the internally formed space-charge field and the external electric field. Furthermore, the photorefractive optical diffraction response time of triphenyl amine-based polymers is of the order of millisecond and submillisecond, which exceeds the video rate. , High optical diffraction and the large area size of PR polymer films enable holographic display applications. ,,− Furthermore, the flexibility of the photorefractive films has an advantage of application in flexible devices …”