Contrasting effects of compressive and tensile strain and doping-induced opening of charge-transfer gap in NdNi[sub 0.90]Mn[sub 0.10]O[sub 3] thin films

In this study, a flexible strain sensor is devised using corrugated bilayer thin films consisting of poly(3-hexylthiophene) (P3HT) and poly(3,4-ethylenedioxythiophene)-polystyrene(sulfonate) (PEDOT:PSS). In previous studies, the P3HT-based photoactive non-corrugated thin film was shown to generate direct current (DC) under broadband light, and the generated DC voltage varied with applied tensile strain. Yet, the mechanical resiliency and strain sensing range of the P3HT-based thin film strain sensor were limited due to brittle non-corrugated thin film constituents. To address this issue, it is aimed to design a mechanically resilient strain sensor using corrugated thin film constituents. Buckling is induced to form corrugation in the thin films by applying pre-strain to the substrate, where the thin films are deposited, and releasing the pre-strain afterwards. It is known that corrugated thin film constituents exhibit different optical and electronic properties from non-corrugated ones. Therefore, to design the flexible strain sensor, it was studied to understand how the applied pre-strain and thickness of the PEDOT:PSS conductive thin film affects the optical and electrical properties. In addition, strain effect was investigated on the optical and electrical properties of the corrugated thin film constituents. Finally, flexible strain sensors are fabricated by following the design guideline, which is suggested from the studies on the corrugated thin film constituents, and the DC voltage strain sensing capability of the flexible strain sensors was validated. As a result, the flexible strain sensor exhibited a tensile strain sensing range up to 5% at a frequency up to 15 Hz with a maximum gauge factor ~7.

Download Full-text

Dipol- And Charge Transfer Contributions To The Work Function Change Of Semiconducting Thin Films: Experiment And Theory

10.1109/sensor.1995.722009 ◽

2005 ◽

Cited By ~ 1

Author(s):

H. Geistlinger ◽

I. Eisele ◽

B. Flietner

Keyword(s):

Thin Films ◽

Charge Transfer ◽

Work Function ◽

Function Change ◽

Work Function Change ◽

Semiconducting Thin Films

Download Full-text

The Influence of Ordering on the Photoinduced Charge Transfer in Composites of Phenyl-type Substituted Polythiophenes with Methanofullerenes

MRS Proceedings ◽

10.1557/proc-598-bb3.24 ◽

1999 ◽

Vol 598 ◽

Author(s):

Christoph J. Brabec ◽

Christoph Winder ◽

Markus C. Scharber ◽

N. Serdar Sariciftci ◽

Mats R. Andersson ◽

...

Keyword(s):

Thin Films ◽

Charge Transfer ◽

Treatment Results ◽

Generation Efficiency ◽

Charge Generation ◽

Photoinduced Charge Transfer ◽

Strong Electron ◽

Low Energies ◽

Photoinduced Charge ◽

Absorption Measurements

ABSTRACTRegioregular polythiophenes baring 3-(p-methoxyethoxyethoxy)-phenyl substituents (PEOPT) show high photoluminescence efficiencies. Exposing thin films of this polymer to vapors of chloroform or annealing them by heat treatment results in a red shift of the absorption maximum due to solvent or heat induced ordering which gives rise to more planar conformations. The fact, that annealed thin films of PEOPT exhibit absorption edges at relatively low energies and thus have an enhanced spectral range makes them suitable for use in photodiodes / solar cells. The photoinduced charge generation efficiency in PEOPT is significantly enhanced by the addition of a strong electron acceptor like fullerene, as observed by quenching of the luminescence and by photoinduced absorption measurements in the infrared and UV-Vis regime. The efficiency of the photoinduced charge transfer from PEOPT to a methanofullerene is found to depend on the ordering of PEOPT in thin films.

Download Full-text