Pulsed laser deposition of Zn(O,Se) layers in nitrogen background Pressure

Abstract

Zinc oxy-selenide Zn(O,Se) is a novel material, that can replace the toxic CdS buffer layer in thin film solar cells and other optoelectronic devices. In this paper a systematic study of the structural, optical and electrical properties of Zn(O,Se) layers, grown by pulsed laser deposition under 50 mTorr of nitrogen background pressure, over a wide range of the substrate temperature, from RT to 600 °C, is reported. XRD, Raman, HR-SEM, XPS, UV-Vis techniques and Hall effect measurements have been used to investigate the structural, and optoelectronic properties of Zn(O,Se) layers. XRD analysis revealed that the polycrystalline ternary Zn(O,Se) phase formed at 500 °C. Raman analysis confirmed the formation of the polycrystalline Zn(O,Se) phase at 500 °C and an amorphous phase at substrate temperatures below 500 °C. Similarly, XPS analysis accompanied with the modified Auger parameters confirmed formation of ternary Zn(O,Se) layer at 500 °C as well. HR-SEM investigation showed the growth of homogenous, dense and adherent films onto a glass substrate. Furthermore, optical studies revealed that all prepared films are practically transparent in the visible region of the spectrum, with a band gap around 3 eV. Hall effect measurements revealed that conductivity, and electron concentration, increased by four orders of magnitude at 600 °C. It was found, that nitrogen background pressure maintained stable ratios of elemental contents in the whole range of the substrate temperature for Zn(O,Se) layers.

MOFs-Derived Zn-Based Catalysts in Acetylene Acetoxylation

“…The first peak at 530.6 eV refers to the oxygen ion from the Zn-O bond in the lattice of ZnO [ 37 ], leading to zinc atoms existing in the form Zn-O [ 38 ]. The second peak at 531.2 eV is associated with the form of OH existing on the catalysts [ 39 ]. The third peak at 532.5 eV is related to the chemisorbed oxygen on the catalysts [ 40 ].…”

Creation of a facile heterojunction in Co/ZnO–TiO2 for the photocatalytic degradation of alizarin S

“…4a exhibit two characteristic peaks from Zn 2p 3/2 and Zn 2p 1/2 at 1021.5 and 1044.6 eV, respectively, indicating the presence of Zn 2+ in the synthesized materials. 43–45 The Ti 2p XPS spectra in Fig. 4b also display two peaks at 458.5 and 468.1 eV corresponding to Ti 2p 3/2 and Ti 2p 1/2 from Ti 4+ in the synthesized oxides.…”

ZnSe and CdS Co‐Sensitized TiO2Nanorod Arrays as Photoanodes for Bias‐Free Solar Hydrogen Evolution

“…The extensive analysis confirms the nature of mixed LO phonon modes of heterostructure photoanode. A small hump at 570 cm −1 was assigned to intrinsic Se vacancies in ZnSe as a result of its non‐stoichiometric composition due to the binding of Zn with O in the TiO 2 lattice [35,36] …”

“…A small hump at 570 cm À 1 was assigned to intrinsic Se vacancies in ZnSe as a result of its nonstoichiometric composition due to the binding of Zn with O in the TiO 2 lattice. [35,36] Interestingly, in the CdS/ZnSe/TiO 2 photoanode, the peak associated with CdS was less intense and broader compared to the ZnSe deposition over the TiO 2 and causes the main vibration mode of E g (TiO 2 ) to position out with diminutive shift (about 6 cm À 1 ) for the heterostructure samples. [37] By considering that the broad E g anatase mode at 148 cm À 1 is associated with the SeÀ Zn(Cd)À OÀ TiÀ O vibration, the presence of ZnSe and CdS on the TiO 2 lattice could probably cause a vibration distortion resulting in broadband.…”