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The influence of palladium doping on the structural, morphological, optical and electronic properties of formamidinium lead iodide perovskite films
(2025-12-01)
Wechprasit, Tirapat
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Bootchanont, Atipong
;
Infahsaeng, Yingyot
;
Wongjom, Poramed
;
Wannapaiboon, Suttipong
In this study, we investigated the effects of palladium (Pd) doping on the properties of formamidinium lead iodide (FAPbI<inf>3</inf>) perovskite films. Pd was doped at concentrations ranging from 0.5 to 2 % and coated onto indium tin oxide (ITO) glass substrates using a spin-coating technique. The crystal structure of the films was characterized using X-ray diffraction (XRD), revealing that Pd-doping reduces the hexagonal phase while increasing the cubic phase in the FAPbI<inf>3</inf> lattice. The optical properties were evaluated using ultraviolet–visible spectrophotometry (UV–Vis), showing changes in light absorption and a reduction in the energy gap with Pd incorporation. Scanning electron microscopy (SEM) was employed to examine the morphological properties of the films, indicating significant surface alterations and formation of larger grain sizes due to Pd incorporation. The electronic structure of perovskite films was thoroughly investigated using X-ray photoelectron spectroscopy (XPS). These findings demonstrate that Pd-doping significantly affects the structural, optical, and electronic properties of FAPbI<inf>3</inf> perovskite films, with potential implications for enhancing the performance of perovskite-based devices.
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Synchrotron-based NEXAFS analysis of thermal-treated diamond-like carbon films
(2020-10-01)
Chunjaemsri, Thanun
;
Chanlek, Narong
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Sukkha, Usa
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Nakajima, Hideki
;
Rujirawat, Saroj
Diamond-like carbon (DLC) film properties are known to vary with important factors such as the ratio of sp3 to sp2 hybridization, film thickness, and contaminations. In this work, the carbon bonding contents in DLC thin films, thermal-treated with various temperatures between room temperature to 250 °C, were studies by near-edge X-ray absorption fine structure (NEXAFS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. From NEXAFS measurements, the sp3/sp2 ratios of DLC films were found to be unaffected by the thermal treatments. The results indicate that thermal treatment below 250 °C does not affect the carbon bonding contents in DLC thin film.
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Characterisation of thermal oxide scales on stainless steels
(2020-01-01)
Srisrual, Anusara
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Thublaor, Thammaporn
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Wongpromrat, Patthranit
This chapter aims at reviewing the characterisation techniques that are commonly used for high temperature oxidation study, especially on stainless steels. In addition, the experimental studies about the high temperature oxidation i.e. thermogravimetric method and chromium volatilisation measurement are explained. The various kinds of characterisation techniques for physico-chemical and electronic properties of thermal oxide scales are reviewed, starting from optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), focused ion beam coupled with scanning electron microscope (FIB/SEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (RS), and photoelectrochemical characterisation (PEC). The review focuses on the basic concepts and shows how the characterising tools can be applied to thermal oxide characterisation.
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Photoluminescence and X-ray photoelectron spectroscopic study of milled-ZnO material prepared by high energy ball milling technique
(2020-01-01)
Mekprasart, Wanichaya
;
Ravuri, Balaji R.
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Yimnirun, Rattikorn
;
Pecharapa, Wisanu
Luminescence properties that are correlated to near band edge emission and defect-related emission of milled zinc oxide (ZnO) powder prepared by high energy ball milling technique are investigated. Commercial ZnO powder (particle size of 525 nm) was chosen as starting material in milling process to produce ultrafine ZnO powder. The milling process was carried out at different speeds; 0, 200, 400 and 600 rpm for 10 min. After milling at high speed, change in color of milled ZnO powder was clearly observed that could be due to the defects in ZnO structure induced by mechanical strain during milling process. Surface morphology of milled ZnO powder was monitored by field-emission scanning electron microscopy (FESEM). Element component and surface chemical states of the samples were analyzed by X-ray photoelectron spectroscopy (XPS). Optical property of milled samples was investigated by diffuse reflectance UV-Vis spectrometer. Meanwhile, room-temperature photoluminescence spectroscopy of the milled samples was performed. The milled ZnO particle size was distinctly decreased to ca. 200 nm affirmed by FESEM images. Photoluminescence (PL) spectra of milled ZnO sample showed two prominent emission bands; UV and visible region. Visible emission intensity increased with increasing milling speed that would be attributed to greater structural defects caused by high mechanical strain during milling process.
1
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Study on optical and electronic properties of Sn-doped ZnPc
(2013-10-29)
Rangkasikorn, Adirek
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Sributr, Chaloempol
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Rojanasuwan, Sunit
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Tammarugwattana, Narin
;
Mano, Kitipong
Sn doped ZnPc films were deposited on intrinsic Si and glass substrates by organic source thermal co-evaporation technique with different deposition rates. Optical properties and electronic structure were characterized by UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) respectively. The UV-Vis results showed that phase transition of ZnPc from α- phase to β-phase occurred when Sn:ZnPc deposition rate is 0.3:0.7 or higher. XPS results indicated that the outer s electron of Sn atom is transferred to the ZnPc. Broadening of the C 1s spectra is observed with the increasing of Sn deposition rate. This broadening corresponds to the change of molecular environment surrounding carbon atoms in the Sn-doped ZnPc films. © (2013) Trans Tech Publications, Switzerland.
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