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Deposition of PEDOT: PSS Films By Infrared Laser Vaporization

Abstract
Thin 美国范德比尔特大学电子激光研究论文 films of poly (3, 4-ethylenedioxythiophene)-poly (styrene suffocates) were deposited by resonant infrared laser vaporization from a frozen PEDOT: PSS target. The deposited films were continuous, and exhibited morphological and structural properties similar to those of the starting material, as measured by scanning electron microscopy and Fourier-transform infrared spectroscopy, suggesting that vacuum phase deposition may be practical

1. Introduction
Poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate), (abbreviated hereafter as PEDOT: PSS) is a novel, widely used material in the fabrication of organic light emitting devices (OLEDs) [1, 2]. Its high conductivity and near transparency in thin film form make it a perfect candidate for an anode or hole-transport layer (HTP) in an OLED. The inherent difficulty in its processing, however, has proven to be an obstacle to efficiently manufacturableand reliable devices. An all-vacuum process, which is desirable in the fabrication of any high performance electronic device, is not presently possible due to the current processing methods of PEDOT: PSS, which is usually deposited via a spin-coat technique. It’s clear that an alternative deposition process is highly desirable, one that does not require the exposure of the device to atmosphere during fabrication.

Recent published reports show that it is possible to transfer number of organic and polymeric materials from a bulk sample into a thin film by way of infrared laser ablation from neat or frozen targets [3-5]. In infrared laser vaporization (IR-LVD), the target may be either a solid neat disk or a frozen target containing the material to be deposited in a suitable carrier. Infrared laser radiation, tuned to a weak vibration resonance of the target, is then focused onto the target under vacuum. The incident radiations absorbed by the matrix, generating a plume of ablated material that subsequently condenses onto a nearby substrate. In the case of frozen targets, the solvent is typically pumped away in the process and the heavier organic is deposited as a thin film. PEDOT: PSS — the standard suspension used for liquid-phase deposition of PEDOT, since PEDOT itself is insoluble — lends itself conveniently to this process. IR-LVD differs from matrix-assisted pulsed-laser evaporation (MAPLE) process using ultraviolet excimerlasers [6] in two fundamental ways: (1) it does not rely on the use of a strong electronic excitation to initiate the phase change and vaporization of the matrix, and hence does not require the use of volatile organic matrix material; and (2) the IR-LVDprocess does not produce significant electronic excitation because vaporization is induced by vibration excitation. Thus IR-LVDavoids the principal vaporization mechanisms capable of inducing photochemical damage to the target material. Also, because of the greater penetration depth of the IR laser in the matrix material, vaporization and deposition rates are substantially higher than those characteristic of UV-MAPLE.

6. References
[1] L. Groenendaal, G. Ziti, and F. Jonas, “Optical, conductive and magnetic properties of electrochemically prepared alkylatedpoly (3, 4-ethylenedioxythiophene) s,” Synthetic Metals118 (1-3), 105-109, 2001.
[2] F. Lou wet, L. Groenendaal, J. Dane, J. Manna, and J. Van Lupine. Verdonck, and L. Lenders, “PEDOT/PSS: synthesis, 本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。