학술논문

Time dynamics of self-pumped reflection gratings in a photorefractive polymer.
Document Type
Article
Source
Journal of Applied Physics. Jan2012, Vol. 111 Issue 1, p013108. 4p. 1 Diagram, 4 Graphs.
Subject
*PHOTOREFRACTIVE materials
*POLYMERS
*HOLES (Electron deficiencies)
*CHARGE carrier capture
*ELECTRIC fields
*ELECTRON mobility
*DIFFRACTION gratings
Language
ISSN
0021-8979
Abstract
The time dynamics of self-pumped reflection gratings in a commonly used photorefractive polymer PDCST:PVK:ECZ-BBP:C60 with no additional electron sources or traps is investigated. While holes are normally the mobile charges and responsible for grating formation, our experimental observations, analyzed using multi-exponential fitting curves, show evidence of electrons in addition to holes as charge carriers, particularly above an applied field of 40 V/μm. The dependence of effective carrier mobilities on the applied electric field, deduced from experimental results, show stronger field dependence of electron mobility at high electric fields. At an applied field of 70 V/μm, electron and hole mobilities become approximately equal, and the contribution of electrons on grating formation becomes significant. [ABSTRACT FROM AUTHOR]