Synergistic Approach toward Erbium-Passivated Triple-Anion Organic-Free Perovskite Solar Cells with Excellent Performance for Agrivoltaics Application

All-inorganic perovskite solar cells (IPSCs) have gained massive attention due to their less instability against common degradation factors (light, heat, and moisture) than their organic-inorganic hybrid counterparts. Inorganic perovskites bear a general formula of CsPbX₃ (X = Cl, I, Br). The mixed halide CsPbIBr₂ perovskite possesses an intermediate band gap of 2.03 eV with enhanced stability, which is still available for photovoltaic applications and the research focus of this work. We present a synergistic approach of pre-heated solution dropping with inorganic additive inclusion to deposit the organic-free triple anion CsPbIBr₂ PSC. Erbium (Er)-passivated triple-anion CsI(PbBr₂)_0.97(ErCl₃)_0.03 IPSCs with inorganic carrier selective layers (CTLs), that is, organic-free, are fabricated with enhanced carrier diffusion length and crystalline grain size while lessening the grain boundaries near perovskite active layer (PAL)-bulk/carrier selective interfaces. As a result, the trap-state densities within the perovskite bulk were suppressed with stabilized CTL/PAL interfaces for smooth and enhanced carrier transportation. Therefore, for the first time, we contradict the common belief of V_OC loss due to halide segregation, as a nice V_OC of about 1.34 V is achieved for an organic-free IPSC through enriching initial radiative efficiency, even when halide segregation is present. The optimized organic-free IPSC yielded a power conversion efficiency of 11.61% and a stabilized power output of 10.72%, which provides the potential opportunity to integrate into agrivoltaics (AgV) projects.

Blueshifted dielectric properties and optical conductivity of new nanoscale nickel-(II)-tetraphenyl-21H,23H-porphyrin films as a function of UV illumination for energy storage applications

Pristine thermally evaporated nickel-(II)-tetraphenyl-21H,23H-porphyrin (NiTPP) thin films are amorphous, but after 4 and 8 h of UV illumination, the films become crystalline with preferred orientations of (112), (103) and (004) and crystallite sizes of (13, 18, 16) and (42, 31, 38) nm after 4 and 8 h, respectively. After UV illumination for 4 and 8 h, the NiTPP thin films are characterized by blueshifted absorption coefficients, increasing the optical and fundamental gap values and decreasing the dispersion parameter values. The dielectric properties display energy storage regions corresponding to the peak values of optical conductivity, which provides an elegant confirmation of the tailoring and tuning of band gaps, energy storage properties and optical conductivity by UV illumination time. Therefore, NiTPP films may be good candidates for environmental and energy storage applications.

Dependence of new environmental nano organic semiconductor nickel-(II)-tetraphenyl-21H,23H-porphyrin films on substrate type for energy storage applications

Characterization of organic nickel-(II)-tetraphenyl-21H,23H-porphyrin films as a function of substrate type was performed for energy storage applications and consequently environmental enhancement. Nickel-(II)-tetraphenyl-21H,23H-porphyrin films show an amorphous phase. They have a crystallite size of 8-11 nm. Strain caused a shift of different humps' positions. The measured transmittance has high values within the range of 85-91%, and the absorption coefficient values were included within the high-absorption region. Both optical gap and fundamental gap, refractive index, carrier-concentration-to-effective-mass ratio and lattice dielectric constant were calculated, and they were found to be increased, except refractive index and lattice dielectric constant. The obtained data indicated that nickel-(II)-tetraphenyl-21H,23H-porphyrin films are a candidate for energy storage applications.

Synthesis, thermal behavior and optical characterizations of thin films of a novel thiazole azo dye and its copper complexes

In the present paper, a novel dye of 4-methyl-5-(4-acetylphenyldiazenyl)thiazol-2-amine (L) and its corresponding copper complexes are synthesized and characterized using different techniques including elemental analysis, thermal analysis, ¹H NMR, Mass, and FT-IR spectra. The thermal behavior of L and its complexes is carried out and discussed using thermogravimetric analysis, and it observed that the type of copper substituent affects the thermal decomposition of complexes. Homogenous thin films of L and its complexes are successfully grown onto quartz substrates using spin coating technique. Optical features and spectral phenomena of the thin films are studied using spectrophotometric measurements of absorbance, transmittance and reflectance. The optical constants such as refractive index, extinction coefficient, optical conductivity and energy loss functions of the thin films of L and its complexes are calculated. The refractive index curves for all films show a normal dispersion behavior in the non-absorbing region of spectra, from which the dispersion parameters can be calculated using Wemple-DiDomenico model. The type of optical transition bands shows indirect allowed. The values of the optical energy gap are calculated in the range from 2.13 to 2.33 eV, depending on the nature of Cu(II) substituent. Indeed, the present results show that the complexes as organic semiconductors acquired good characterizations better than metal free ligand (L) such as more thermal stability, reducing in the optical band gap and increasing in the absorption coefficient that refers to light harvesting capacity.

Influence of gamma ray irradiation and annealing temperature on the optical constants and spectral dispersion parameters of metal-free and zinc tetraphenylporphyrin thin films: A comparative study

In this work, we report on the effect of γ-ray irradiation and annealing temperature on the optical properties of metal-free tetraphenylporphyrin, H2TPP, and zinc tetraphenylporphyrin, ZnTPP, thin films. Thin films of H2TPP and ZnTPP were successfully prepared by the thermal evaporation technique. The optical properties of H2TPP and ZnTPP films were investigated using spectrophotometric measurements of the transmittance and reflectance at normal incidence of light in the wavelength range from 200 to 2500 nm. The absorption spectra of H2TPP showed four absorption bands, namely the Q, B, N and M bands. The effect of inserting Zn atom into the cavity of porphyrin macrocycle in ZnTPP molecule distorted the Q and B bands, reduced the width of absorption region and influenced the optical constants and dispersion parameters. In all conditions, the type of electron transition is indirect allowed transition. Anomalous dispersion is observed in the absorption region but normal dispersion occurs in the transparent region of spectra. We adopted multi-oscillator model and the single oscillator model to interpret the anomalous and normal dispersion, respectively. We have found that the annealing temperature has mostly the opposite effect of γ-ray irradiation on absorption and dispersion characteristics of these films.

Optical absorption of tetraphenylporphyrin thin films in UV-vis-NIR region

The optical absorption of thermally evaporated tetraphenylporphyrin (TPP) in the UV-vis-NIR region have been studied. The absorption spectra recorded in the UV-vis region for the as deposited and annealed films showed different absorption bands, namely the Soret(B) at region 360-490nm, Q-band region consist of four bands in the region 500-720nm and two other bands labeled N and M in UV region. The Soret band always shows its characteristic effect splitting in all the TPP thin films and the effect of annealing on the intensities of these components have been observed. The spectra of the infrared absorption allow characterization of vibrational modes for the powder, as deposited and annealed thin films. Some of the optical absorption parameters, namely molar extinction coefficient, epsilon, half band width, Deltalambda, electronic dipole strength, q(2) and oscillator strength, f, of the principle optical transitions have also been evaluated.

Optical absorption of tetraphenylporphyrin thin films in UV-vis-NIR region

The optical absorption of thermally-evaporated tetraphenylporphyrin (TPP), in the UV-vis-NIR region has been studied. The absorption spectra recorded in the UV-vis region for the as-deposited and annealed films showed different absorption bands, namely the Soret, B, at region 360-490 nm, Q-band region consist of four bands in the region 500-720 nm and two other bands labeled N and M in UV region. The Soret band always shows splitting in all the TPP thin films and the effect of annealing on the intensities of these components have been observed. The spectra of the infrared absorption allow characterization of vibrational modes for the powder, as deposited and annealed thin films. Some of the optical absorption parameters, namely molar extinction coefficient (epsilon), half band width (Deltalambda), electronic dipole strength (q2), and oscillator strength (f), of the principal optical transitions have also been evaluated.

Falls among institutionalized elderly in Alexandria

Falls are a common geriatric problem causing considerable morbidity, mortality, and affecting the quality of life of many elderly people. A cross sectional study was conducted to determine the prevalence and risk factors of falls among elderly people living in geriatric institutions in Alexandria. The total sample included 103 elderly females and 62 elderly males from six institutions. All participants were subjected to interviewing questionnaire to collect data about history, circumstances, outcome of falls, previous falls and history of diseases and drug intake It included also data about activities of daily living. Anthropometric measurements, blood pressure, postural hypotension assessment, complete physical examination and Tinetti scale for balance and gait could be completed for a sub-sample. The prevalence of falls was 32.1%. Most of the falls occurred during the daytime (77.4%), mainly in the bedroom or in the way from bed to bathroom (37.7% each). The most likely causes were slip/trip (41.5%) followed by dizziness/vertigo (32.1%). Fractures occurred in 20.8% of falls. Advanced age (70-79, 80 years and above), history of three or more falls, history of disability from previous falls, history of visual problem, history of cardiac and antihypertensive drug use, and mild impairment of balance and gait were significant risk factors for falls in the univariate analysis. All these factors except for the impairment of balance and gait were also significant predictors of falls in the multivariate analysis.

Detection of circulating antigens in patients with active Schistosoma haematobium infection

An antigen-capture ELISA using monoclonal antibody (MAb) 128C3/3/21 was used to detect circulating parasite-derived antigens in the sera of patients actively infected with Schistosoma haematobium (31 males and four females, 5-25 years of age). The assay had a sensitivity of 100% (35 of 35 patients with antigen levels > 80 ng/ml) and a specificity > 99%. We used this ELISA to monitor antigenemia before treatment and one, three, and six months after treatment with a single oral dose of praziquantel (PZQ) (60 mg/kg in 20 patients or 40 mg/kg in 15 patients) and compared our findings with those indicated by other measures of disease progression. Circulating antigen levels decreased drastically after PZQ treatment (P < 0.001), with a significantly higher decrease occurring after treatment with 60 mg/kg than with 40 mg/kg. Although the mean antigen level was still significantly reduced (P < 0.001) at six months after treatment, 16 patients remained antigen-positive after six months, and nine had increased levels of antigenemia, reflecting reinfection in six patients and persistence of infection in another. We observed a correlation (r = 0.6, P < 0.01) between the level of circulating antigen and the intensity of infection as measured by egg count. We also found a direct relationship (P < 0.001) between antigen level and the severity of the disease as monitored by ultrasonography. We conclude that our ELISA may be a useful adjunct to other methods, such as ultrasonography, for monitoring the course of S. haematobium infection and treatment.

Acute viral hepatitis in pregnancy

OBJECTIVE

To describe the clinical outcome of pregnancy and vertical transmission of acute viral hepatitis in pregnancy.

METHODS

Forty-eight pregnant patients with acute viral hepatitis were evaluated clinically and by abdominal ultrasonography. Serological studies for hepatitis markers were performed using radioimmunoassay. The results were evaluated using Student's t-test and tests of proportion.

RESULT

Thirty-five (72.9%) delivered live birth babies at term, while 13 (27.1%) had fetal complications and/or losses. The percentage of fetal complications and/or losses was higher in patients who had non-A, non-B hepatitis (30.8%) than those who had type B hepatitis (25%). The most common fetal complication was premature delivery (14.9%) followed by stillbirth and abortion (8.3%) for each. The overall percentage of vertical transmission of hepatitis B virus was 2 out of 27 (7.4%).

CONCLUSION

Acute viral hepatitis carries a high risk for both mother and fetus. Routine vaccination of all susceptible women and babies against hepatitis B is recommended in endemic areas.