Methods for probing charging properties of polymeric materials using XPS

Sezen, Hikmet
Ertaş, Gülay
Suzer, Sefik
Various thin polystyrene, PS, and poly(methyl methacrylate), PMMA and PS + PMMA blend films have been examined using the technique of recording X-ray photoelectron spectrum while the sample is subjected to +/- 10 V d.c, bias, and three different forms of (square-wave (SQW), sinusoidal (SIN) and triangular (TRG)), a.c. pulses. All films exhibit charging shifts as observed in the position of the corresponding C1s peak under d.c. bias. The a.c. pulses convert the single C1s peak to twinned peaks in the case of the square-wave form, and distort severely in the cases of the SIN, and TRG forms, and all three of them exhibit strong frequency dependence. In order to mimic and better understand the behavior of these polymeric materials, an artificial dielectric system consisting of a clean Si-wafer coupled to an external 1 M Omega resistor and 56 nF capacitor is created, and its response to different forms of voltage stimuli, is examined in detail. A simple electrical circuit model is also developed treating the system as consisting of a parallel resistor and a series capacitor. With the help of the model, the response of the artificial system is successfully calculated as judged by comparison with the experimental data. Using one high frequency SQW measurements, the off-set in the charging shift clue to the extra low-energy neutralizing electrons is estimated. After correcting the corresponding off-set shifts, the XPS spectra of the three different PS films, one PMMA, and one PS + PMMA blend film are re-examined. As a result of these detailed analysis, there emerges a clear relationship between the thicknesses of the PS films with their charging abilities. In the blend film, PS and PMMA domains are electrically separated, and exhibit different charging shifts, however, the presence of one is felt by the other. Hence, the PS component shifts are larger in the blend, due to the presence of PMMA domains, which has intrinsically a larger R-eff, and conversely the PMMA component shifts are smaller due to the presence of PS domains.


Characterization of GZO thin films fabricated by RF magnetron sputtering method and electrical properties of In/GZO/Si/Al diode
Surucu, O. Bayrakli (Springer Science and Business Media LLC, 2019-11-01)
The main focus of this work is the structural and optical characterization of Ga-doped ZnO (GZO) thin film and determination of the device behavior of In/GZO/Si/Al diode. GZO thin films were deposited by RF magnetron sputtering technique from single target. The structural and morphological properties of GZO film were investigated by X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy analysis (EDS) measurements. Optical properties of the fil...
The nonlinear and saturable absorption characteristics of Ga0.90In0.10Se and Ga0.85In0.15Se semiconductor crystals and their amorphous thin films
KARATAY, AHMET; Aksoy, Cagla; YAĞLIOĞLU, HALİME GÜL; ELMALI, Ayhan; Kurum, Ulas; ATEŞ, AYTÜNÇ; Hasanlı, Nızamı (IOP Publishing, 2011-07-01)
We investigated the nonlinear and saturable absorption characteristics of Ga0.90In0.10Se and Ga0.85In0.15Se semiconductor crystals and their very thin amorphous films by open aperture (OA) Z-scan and pump-probe techniques. The linear absorption spectra indicated a blue shift in energy with increasing film thickness. This can be attributed to the quantum confinement effect. For both 4 ns and 65 ps pulse durations the two photon absorption coefficients of Ga0.90In0.10Se and Ga0.85In0.15Se crystals increased w...
Investigation of optical parameters of Ag-In-Se thin films deposited by e-beam technique
ÇOLAKOĞLU, TAHİR; Parlak, Mehmet; ÖZDER, SERHAT (Elsevier BV, 2008-07-15)
The optical properties of the Ag-In-Se (AlS) thin films deposited by e-beam technique were investigated by means of the optical transmittance measurements. The optical absorption coefficients of the films were found to vary from 10(3) to 10(5) cm(-1) over the wavelength range of 300-1100 nm. The real and imaginary parts of the refractive index and dielectric constant for the as-grown and annealed films in between 100 and 400 degrees C were evaluated by means of both envelope method (EM) and continuous wavel...
Investigation of electrical characteristics of Ag/ZnO/Si sandwich structure
Gullu, H. H.; Surucu, O. Bayrakli; Terlemezoğlu, Makbule; Yildiz, D. E.; Parlak, Mehmet (Springer Science and Business Media LLC, 2019-08-01)
In this study, temperature-dependent current-voltage (I-V), frequency-dependent capacitance-voltage (C-V) and conductance-voltage (G/omega-V) measurements are carried out for the electrical characterization of a zinc oxide (ZnO) thin film-based diode. The sandwich structure in the form of Ag/ZnO/Si/Al is investigated at temperatures between 220 and 360 K and in the frequency region of 1 kHz-1 MHz. ZnO thin film layer is deposited on a p-Si wafer substrate as a transparent conductive oxide layer by taking in...
Effects of screening on the two-dimensional electron transport properties in modulation doped heterostructures
Sen, O; Beşikci, Cengiz; Tanatar, B (Elsevier BV, 1998-06-01)
The effects of screening on the polar optical phonon scattering rates and on the transport properties of the two-dimensional electron gas in AlGaAs/GaAs modulation doped heterostructures have been investigated through Monte Carlo simulations incorporating the three valleys of the conduction band, size quantization in the Gamma valley and the lowest three subbands in the quantum-well. At typical sheet densities observed in modulation doped field-effect transistors, screening considerably affects the electron...
Citation Formats
H. Sezen, G. Ertaş, and S. Suzer, “Methods for probing charging properties of polymeric materials using XPS,” JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA, pp. 373–379, 2010, Accessed: 00, 2020. [Online]. Available: