Realizing Saturable Absorption and Reverse Saturable Absorption in a PEDOT:PSS Film via Electrical Modulation

Date

2020-10-19

Authors

Sun, Yanhui
Li, Hui
Hou, Ruipeng
Diao, Mengjuan
Liang, Ying
Huang, Zhipeng
Humphrey, Mark
Zhang, Chi

Journal Title

Journal ISSN

Volume Title

Publisher

American Chemical Society

Abstract

Electrical tuning of the nonlinear absorption of materials has promising application potential, while studies remain rare. In this work, we show that the third-order nonlinear absorption of poly(3,4-ethylenedioxythiophene) chemically doped with poly(styrene sulfonic acid) [PEDOT:PSS] can be effectively modulated by external voltage. The nonlinear absorption of the film can be varied between reverse saturable absorption (RSA) and saturable absorption (SA) via voltage control with laser excitation at 800 nm, and the corresponding nonlinear absorption coefficient can be tuned in the range -1606 +- 73 to 521 +- 9 cm GW-1. The doping level and energy structure of PEDOT are modulated with different voltages. The undoped film affords two-photon absorption and accordingly the RSA response. A moderately doped sample has two polaron levels, and Pauli blocking associated with these two polaron levels results in SA. The bipolaron level in heavily doped PEDOT leads to excited-state absorption and therefore RSA behavior. The approach reported here can be applied to other semiconductors and is a convenient, effective, and promising method for the electrical tuning of the optical nonlinearity.

Description

Keywords

PEDOT, conductive polymer, nonlinear optical, electrical control, polaron

Citation

Source

ACS Applied Materials and Interfaces

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

DOI

10.1021/acsami.0c14447

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