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For reducing the production costs, decreasing the fabrication time and for practical applications used in roll-to-roll process for inverted organic solar cells (IOSCs), silver (Ag) back-electrode have been deposited from silver paste solution at room temperature using simple, cheap and easy manual spray method, with completely avoiding the use of thermal evaporation system for solar cell preparation. In addition, a layer of poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) as a hole transporting layer have been deposited from an aqueous solution onto hydrophobic active layer without any chemical additives or additional treatments. For optimizing the Ag film, to be used as a back electrode in the IOSCs, series resistance of the indium tin oxide (ITO)/PEDOT:PSS/Ag device was measured at different compositions of silver paste dispersed in ethanol, different annealing temperatures and different silver paste amounts sprayed onto PEDOT:PSS layer. The dilution process of silver paste with ethanol is practical to reduce its commercial cost and to decrease its viscosity to be easily sprayed using spray gun for application in large scale production with avoiding solidification and fast curing at room temperature. Using the present method, the Ag electrode has been efficiently sprayed on the top of organic solar cells with low electrical resistance, large thickness and good hardness against crashes. We found that, the high thickness of both PEDOT:PSS layer and Ag electrode deposited on the top of solar cell active layer prevent and suppress oxygen penetration towards P3HT:PCBM active layer. Therefore, the optimized solar cell revealed good air stability, compared to their counterparts in other literatures, under ambient atmosphere with approximately 86% retention of their original conversion efficiency after 154 days. Our results indicate that the solution-processed Ag back-electrode using easy method has a potential to be used in roll-to-roll processed organic solar cells and other optoelectronic applications.

A new glass system (50−x)P2O5–20B2O3–5Al2O3–25Na2O–xCoO was manufactured using a standard melt quenching procedure, where 1≤ x ≤ 12 mol%. The characteristics of boro-phosphate-glasses containing CoO have been studied. The effect of CoO on the radiation-protective properties of glasses was established. The density of the prepared glasses as a function of CoO increased. XRD was used to check the vitreous structure of samples. Fourier-transform infrared (FTIR) spectroscopy was used to study the structure of each sample. FTIR demonstrated that connections grew as CoO/P2O5 levels increased, and the FTIR spectra shifted to higher wavenumbers. The increment of CoO converts non-bridging oxygens associated with phosphate structural units into bridging oxygens. This process increases the concentration of BO4 structural units and creates new, strong and stable bonds B–O–P, i.e., there is polymerization of the boro-phosphate glass network. With an increase in the ratio of CoO/P2O5 in the produced samples, ultrasonic velocities and elastic moduli were observed to increase. The coefficients of linear and mass attenuation, the transmittance of photons in relation to the photon energy, the efficiency of radiation protection in relation to the photon energy, and the thickness of the absorber were modeled using these two methods (experimental and theoretical). From the obtained values, it can be concluded that the 12Co sample containing 12 mol% will play the most influential role in radiation protection. An increase in the content of cobalt-I oxide led to a significant increase in the linear and mass attenuation coefficient values, which directly contributes to the development of the radiation-protective properties of glass.

A new glass system (50−x)P2 O5 –20B2 O3 –5Al2 O3 –25Na2 O–xCoO was manufactured using a standard melt quenching procedure, where 1≤ x ≤ 12 mol%. The characteristics of boro-phosphate-glasses containing CoO have been studied. The effect of CoO on the radiation-protective properties of glasses was established. The density of the prepared glasses as a function of CoO increased. XRD was used to check the vitreous structure of samples. Fourier-transform infrared (FTIR) spectroscopy was used to study the structure of each sample. FTIR demonstrated that connections grew as CoO/P2 O5 levels increased, and the FTIR spectra shifted to higher wavenumbers. The increment of CoO converts non-bridging oxygens associated with phosphate structural units into bridging oxygens. This process increases the concentration of BO4 structural units and creates new, strong and stable bonds B–O–P, i.e., there is polymerization of the boro-phosphate glass network. With an increase in the ratio of CoO/P2 O5 in the produced samples, ultrasonic velocities and elastic moduli were observed to increase. The coefficients of linear and mass attenuation, the transmittance of photons in relation to the photon energy, the efficiency of radiation protection in relation to the photon energy, and the thickness of the absorber were modeled using these two methods (experimental and theoretical). From the obtained values, it can be concluded that the 12Co sample containing 12 mol% will play the most influential role in radiation protection. An increase in the content of cobalt-I oxide led to a significant increase in the linear and mass attenuation coefficient values, which directly contributes to the development of the radiation-protective properties of glass. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Funding: This work funding by Deanship of Scientific at Jouf University through research grant no (DSR2020-02-504).

Pr2O3 doped bismuth-phosphate glasses have been produced via an ordinary melt quenching tool. Glasses have a chemical content (5–x) Al2O3–15Na2O–20Bi2O3–60 P2O5 –xPr2O3 with x values between 0 and 2 mol%. The structural and mechanical features of the prepared phosphate-based glasses were investigated. The XRD spectra confined the amorphous type of these glasses. Furthermore, the influence of Pr2O3 on the mechanical features has been explored and related to the structure. The relationship between structural variations and the contents of Pr2O3 has been investigated in terms of FTIR and by the determination of the density and the ultrasonic velocity. The density and the ultrasonic velocities were utilized to calculate the elastic moduli of the glasses. The acquired results indicate that the ultrasonic velocity and the elastic moduli increase as a function of Pr2O3 in the whole explored studied glasses. The analysis of FTIR spectra refers that Pr2O3 is interstitial settled in the phosphate network with [PrO7] associated with covalent Pr–O–P bonds, whereas Bi2O3 and Al2O3 settle on the network with [BiO6], and [AlO6] units. These experimental features coincide with a compact structure and act in a manner that Pr2O3 incorporates the glassy network with plenty of bridging oxygen atoms. These arguments encourage the use of these glasses in radiation shielding materials.

In this study, five different glasses encoded ND1, ND2, ND3, ND4 and ND5 based on (59.5–x) P2O5–30Na2O–10Al2O3–0.5CoO–xNd2O3 (x = 1, 2, 3, 4 and 5 mol%) glass system were fabricated. Using two γ- ray energies emitted from point sources, 356 keV (133Ba) and 662 keV (137Cs), γ-ray attenuation coefficients were measured as a function of the Nd2O3 concentration. The theoretical values of the mass attenuation coefficient were calculated using the XCOM program at 0.015–15-MeV photon energies. As it is underlined in the results section, the mass attenuation coefficient increases as the Nd2O3 concentration increases. X-ray diffraction (XRD) was characterized for fabricated glasses. Moreover, different shielding parameters such as half-value layer (HVL), mean free path (MFP), effective atomic numbers (Zeff), basic gamma-ray attenuation properties such as exposure buildup factors (EBF) and energy absorption buildup factors (EABF) at different penetration depths were calculated. With increasing Nd2O3 additive in glass samples, half-value layer (HVL), average free path (MFP), exposure and energy absorption buildup factor (EBF and EABF) values decrease. On the other hand, Zeff values increase with increasing Nd2O3 additive in glass samples at the photon energy 0.015–15 MeV. The results highlighted that ND5 sample with highest value of Nd2O3 (5 mol%) showed excellent nuclear radiation shielding properties.

In this study, the radiative parameters were acquired from the UV absorption spectra and the luminescence spectra of Er3+ ions doped Er2O3–Al2O3–Na2O–P2O5 glasses. The intensity of each absorption spectrum was utilized to deduce the radiative parameters and the parameters (Ω2, Ω4 and Ω6) of Judd–Ofelt theory. The FTIR and the elastic moduli of the quaternary glasses are also investigated. Analysis of the FTIR suggested that the presence of Er3+ ions created bridging oxygens and polymerized the local structure around atoms. This procedure manifested itself from decreasing the bond length of O–P and increasing the O/P ratio. The polymerization of the phosphate structure increased the ultrasonic velocity and the rigidity of the network. The electrical parameters of the phosphate glasses, such as the frequency and temperature dependence AC conductivity, dielectric loss and dielectric modulus were carried out. The Er3+ ions affected the carrier mobility by decreasing the electrical conductivity and increasing the activation energy. In addition, the frequency and temperature dependence of the dielectric modulus exhibited a Debye-type relaxation behavior.

This study aimed to fabricate a high-density glass sample with superior physical, structural and mechanical properties that can be used in medical and industrial radiation facilities. For the chief purpose of originating a translucent radiation shielding with remarkable mechanical properties, a glass system of a heavy metal oxide alumino-borosilicate glass of composition (5-x)Al2O3–50SrO–25B2O3–20SiO2–xBi2O3 (0≤ x ≤ 5 wt%) was fabricated by traditional melt-quenching technique. XRD curves presented the disappearance of regular sharp lines, affirming the glassy nature of the glass system. Additionally, the determination of experimentally elastic moduli of the translucent glasses showed their good rigidity, along with good elastic constants. The comprehensive analysis of experimentally determined γ-radiation shielding parameters for all the glasses such as linear attenuation coefficient (μ) and mass attenuation coefficient (μm) have been evaluated, and derived μ amounts are in good compliance with deduced FLUKA codes respective μ outcomes. Next, by applying μ outputs, T1/2, and λ were estimated. All glasses possess exemplary absorption ability for the lower energy photons as authenticated by radiation protection efficiency (RPE). In all inspected glasses, comparatively higher density (4.115 g/cm3), greater μ, and RPE, and the minimum T1/2, and λ values were reported for superior Al–Bi4 glass sample.

Quaternary phosphate glasses CoO - Al2O3 - Na2O - P2O5 (CANP) doped with – different concentrations of Nd2O3 had prepared and studied by FTIR, ultrasonic parameters and UV–Vis–NIR techniques. The Judd-Ofelt theory has applied to describe the absorption and luminescence spectra of Nd3+ ions in these glasses. The Judd–Ofelt parameters such as Ω2, Ω4 and Ω6 have evaluated from the intensities of the absorption bands of the optical absorption spectra and used to calculate various radiative parameters such as probabilities of radiative transitions, radiative lifetime and branching ratios for different Nd2O3 doped CANP glasses.

This work reports on the effect of the increment of Fe2O3 in a network of phosphate glasses involving Al2O3, Na2O and PbO by DTA and Mössbauer techniques. The analysis of Mössbauer suggests oxidation of Fe2+ ions in the distorted bipyramidal to Fe3+ in the same site. This procedure creates non-bridging oxygens joined with Fe2+ octa that weakens the phosphate network whenever the Fe2O3 content increases. The thermal parameters of the phosphate network will be affected by this weakness. Thus, both the glass transition temperature (T gl ) and the crystallization peak temperature (T cp ) on the one hand and the activation energies for glass transition E gl and for crystallization (E gl and E cp ) on the other hand will decrease as a function of Fe2O3. This decrease will be discussed following Lasocka’s relationships that present a good correlation between T gl and T cp . Furthermore, the glass transition temperature (T gl ) was correlated with the glass fragility (m) and with the elastic parameters of the phosphate network such as the bulk (K) and shearing (G) moduli.