The structural, optical and photovoltaic properties of Zn-doped MAPbI2Br perovskite solar cells.

The spin coating method was used to deposit MAPbI2Br films on FTO-glass substrates. Zn2+ (zinc) doping was used for these films at intensity rates of 2% and 4%, respectively. XRD analysis proved that MAPbI2Br films had a cubic structure and a crystalline character. 2% Zn doping into the MAPbI2Br film had a modest large grain size (38.09 nm), Eg (1.95 eV), high refractive index (2.66), and low extinction coefficient (1.67), according to XRD and UV-vis analyses. To facilitate and enhance carrier transit, at contacts as well as throughout the bulk material, the perovskite's trap-state densities decreased. The predicted MAPbI2Br valence and conduction band edges are -5.44 and -3.52, respectively. The conduction band (CB) edge of the film that was exposed to Zn atoms has been pressed towards the lower value, assembly it a better material for solar cells. EIS is particularly useful for understanding charge carrier transport, recombination mechanisms, and the influence of different interfaces within the device structure. Jsc is 11.09 mA cm-2, Voc is 1.09, PCE is 9.372% and FF is 0.777. The cell made with the 2% Zn doped into the MAPbI2Br film demonstrated a superior device.

Bandgap Engineering and Enhancing Optoelectronic Performance of a Lead-Free Double Perovskite Cs2AgBiBr6 Solar Cell via Al Doping.

In this study, solar cells based on pure Cs2AgBiBr6 and Al-doped metal were fabricated using the sol-gel spin-coating technique. X-ray diffraction (XRD) analysis confirmed the formation of cubic-structured films for both pure and Al-doped. Notably, the grain size of Al-doped Cs2AgBiBr6 was observed to be larger than that of its pure counterpart. The optical properties of these films were investigated using UV-vis spectroscopy, revealing essential parameters such as the bandgap energy (Eg), refractive index (n), extinction coefficients (k), and dielectric constant. While the pure film exhibited an Eg of 1.91 eV, the Al-doped film demonstrated a slightly lower Eg of 1.82 eV. Utilization of these films in solar cell fabrication yielded intriguing results. The J-V curve shows that the pure solar cell displayed a short-circuit current density (Jsc) of 5.01 mA/cm2, a fill factor (FF) of 0.67, an open-circuit voltage (Voc) of 0.89 V, and an efficiency of 3.02%. Al doping led to improvements, with an increase in Voc to 0.91 V, FF to 0.71, and Jsc to 5.29 mA/cm2. Consequently, the overall efficiency surged to 3.40%, marking a substantial 12.5% enhancement compared with the pure solar cell. These findings underscore the efficacy of Al doping in enhancing the performance of Cs2AgBiBr6-based solar cells.

Bandgap reduction and efficiency enhancement in Cs2AgBiBr6 double perovskite solar cells through gallium substitution.

Lead-free halide double perovskite (LFHDP) Cs2AgBiBr6 has emerged as a promising alternative to traditional lead-based perovskites (LBPs), offering notable advantages in terms of chemical stability and non-toxicity. However, the efficiency of Cs2AgBiBr6 solar cells faces challenges due to their wide bandgap (Eg). As a viable strategy to settle this problem, we consider optimization of the optical and photovoltaic properties of Cs2AgBiBr6 by Gallium (Ga) substitution. The synthesized Cs2Ag0.95Ga0.05BiBr6 is rigorously characterized by means of X-ray diffraction (XRD), UV-vis spectroscopy, and solar simulator measurements. XRD analysis reveals shifts in peak positions, indicating changes in the crystal lattice due to Ga substitution. The optical analysis demonstrates a reduction in the Eg, leading to improvement of the light absorption within the visible spectrum. Importantly, the Cs2Ag0.95Ga0.05BiBr6 solar cell exhibits enhanced performance, as evidenced by higher values of open circuit voltage (Voc), short-circuit current (Jsc), and fill factor (FF), which are 0.94 V, 6.01 mA cm-2, and 0.80, respectively: this results in an increased power conversion efficiency (PCE) from 3.51% to 4.52%. This research not only helps to overcome film formation challenges, but also enables stable Cs2Ag0.95Ga0.05BiBr6 to be established as a high-performance material for photovoltaic applications. Overall, our development contributes to the advancement of environmentally friendly solar technologies.

Tuning phase separation in DPPDTT/PMMA blend to achieve molecular self-assembly in the conducting polymer for organic field effect transistors.

The semiconductor/insulator blends for organic field-effect transistors are a potential solution to improve the charge transport in the active layer by inducing phase separation in the blends. However, the technique is less investigated for long-chain conducting polymers such as Poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno [3,2-b]thiophene)] (DPPDTT), and lateral phase separation is generally reported due to the instability during solvent evaporation, which results in degraded device performance. Herein, we report how to tailor the dominant mechanism of phase separation in such blends and the molecular assembly of the polymer. For DPPDTT/PMMA blends, we found that for higher DPPDTT concentrations (more than 75%) where the vertical phase separation mechanism is dominant, PMMA assisted in the self-assembly of DPPDTT to form nanowires and micro-transport channels on top of PMMA. The formation of nanowires yielded 13 times higher mobility as compared to pristine devices. For blend ratios with DPPDTT ≤ 50%, both the competing mechanisms, vertical and lateral phase separation, are taking place. It resulted in somewhat lower charge carrier mobilities. Hence, our results show that by systematic tuning of the blend ratio, PMMA can act as an excellent binding material in long-chain polymers such as DPPDTT and produce vertically stratified and aligned structures to ensure high mobility devices.

Effect of Mn Doped on Structural, Optical, and Dielectric Properties of BiFe1-xMnxO3 for Efficient Antioxidant Activity.

Manganese-doped bismuth ferrites were synthesized using the coprecipitation method with the green extract Azadirachta indica. Our incorporation of the transition element, manganese, into bismuth ferrites tackles the challenge of increased leakage current often observed in intrinsic bismuth ferrites. We gained key insights through a comprehensive examination of the structural, dielectric, and optical properties of these materials, utilizing Fourier transform infrared spectroscopy (FTIR), impedance spectroscopy, and UV-visible spectroscopy, respectively. The formation of an octahedral geometry was confirmed using the FTIR technique. UV-visible spectroscopy indicated that 2% Mn doping is optimal, while we obtained a low band gap energy (2.21 eV) and high refractive index (3.010) at this amount of doping. The manufactured materials exhibited the typical ferrite-like dielectric response, that is, the dielectric parameter gradually decreased as the frequency increased and then stayed constant in the high-frequency range. Using the diphenylpicrylhydrazyl (DPPH) free radical assay, we also examined the antioxidant activity of bismuth ferrites. We concluded that among different Mn-doped BiFeMnO3-based nanomaterials, the 2 wt % Mn-doped BiFeMnO3 shows the highest antioxidant activity. This finding substantiates the efficacy of the optimized material with regard to its potent antioxidant activity, positioning it as a promising candidate for potential biomedical applications.

A2LiGaI6 (A = Cs, Rb): New lead-free and direct bandgap halide double perovskites for IR application.

Recently, all inorganic double perovskites have drawn a lot of interest as promising solar materials. The optical, structural, thermoelectric, electronic, and mechanical properties of double halide perovskites A2LiGaI6 (A = Cs, Rb) are explored via first-principles calculations with the WIEN2k code, using GGA PBEsol and TB-mBJ potentials. The majority of perovskite materials utilized in the highest-performing solar cells have bandgaps ranging between 1.48 and 1.62 eV. The compounds A2LiGaI6 (A = Cs, Rb) have a direct bandgap of 1.51 eV and 1.55 eV, respectively, and are expected to be useful in solar cells. The optical study shows that there are large absorption bands in the visible region, as determined by the dielectric constant, absorption, and other dependent factors. Their potential for use in solar cells is increased by their absorption in the visible part. The BoltzTraP code has been used to perform thermoelectric studies to assess the electrical, thermal conductivities, and Seebeck coefficient. They are important for construction of thermoelectric generators that harvest heat energy because of their high figure of merit and incredibly low thermal conductivity of lattice at ambient temperature. Furthermore, by examining the spectroscopic limit maximum efficiency, up to 30 % efficiency is predicted for both compositions, which paves the way for the applicability of them in solar energy conversion.

Role of time-dependent foreign molecules bonding in the degradation mechanism of polymer field-effect transistors in ambient conditions.

Long-standing research efforts have enabled the widespread introduction of organic field-effect transistors (OFETs) in next-generation technologies. Concurrently, environmental and operational stability is the major bottleneck in commercializing OFETs. The underpinning mechanism behind these instabilities is still elusive. Here we demonstrate the effect of ambient air on the performance of p-type polymer field-effect transistors. After exposure to ambient air, the device showed significant variations in performance parameters for around 30 days, and then relatively stable behaviour was observed. Two competing mechanisms influencing environmental stability are the diffusion of moisture and oxygen in the metal-organic interface and the active organic layer of the OFET. We measured the time-dependent contact and channel resistances to probe which mechanism is dominant. We found that the dominant role in the degradation of the device stability is the channel resistance rather than the contact resistance. Through time-dependent Fourier transform infrared (FTIR) analysis, we systematically prove that moisture and oxygen cause performance variation in OFETs. FTIR spectra revealed that water and oxygen interact with the polymer chain and perturb its conjugation, thus resulting in degraded performance of the device upon prolonged exposure to ambient air. Our results are important in addressing the environmental instability of organic devices.

Type I interferon autoantibodies in hospitalized patients with Middle East respiratory syndrome and association with outcomes and treatment effect of interferon beta-1b in MIRACLE clinical trial.

Background: Type I interferons (IFNs) are essential antiviral cytokines induced upon respiratory exposure to coronaviruses. Defects in type I IFN signaling can result in severe disease upon exposure to respiratory viral infection and are associated with worse clinical outcomes. Neutralizing autoantibodies (auto-Abs) to type I IFNs were reported as a risk factor for life-threatening COVID-19, but their presence has not been evaluated in patients with severe Middle East respiratory syndrome (MERS). Methods: We evaluated the prevalence of type I IFN auto-Abs in a cohort of hospitalized patients with MERS who were enrolled in a placebo-controlled clinical trial for treatment with IFN-ß1b and lopinavir-ritonavir (MIRACLE trial). Samples were tested for type I IFN auto-Abs using a multiplex particle-based assay. Results: Among the 62 enrolled patients, 15 (24.2%) were positive for immunoglobulin G auto-Abs for at least one subtype of type I IFNs. Auto-Abs positive patients were not different from auto-Abs negative patients in age, sex, or comorbidities. However, the majority (93.3%) of patients who were auto-Abs positive were critically ill and admitted to the ICU at the time of enrollment compared to 66% in the auto-Abs negative patients. The effect of treatment with IFN-ß1b and lopinavir-ritonavir did not significantly differ between the two groups. Conclusion: This study demonstrates the presence of type I IFN auto-Abs in hospitalized patients with MERS.

Heterogeneity of treatment effect of interferon-ß1b and lopinavir-ritonavir in patients with Middle East respiratory syndrome by cytokine levels.

Animal and human data indicate variable effects of interferons in treating coronavirus infections according to inflammatory status and timing of therapy. In this sub-study of the MIRACLE trial (MERS-CoV Infection Treated with a Combination of Lopinavir-Ritonavir and Interferon ß-1b), we evaluated the heterogeneity of treatment effect of interferon-ß1b and lopinavir-ritonavir versus placebo among hospitalized patients with MERS on 90-day mortality, according to cytokine levels and timing of therapy. We measured plasma levels of 17 cytokines at enrollment and tested the treatment effect on 90-day mortality according to cytokine levels (higher versus lower levels using the upper tertile (67%) as a cutoff point) and time to treatment (≤ 7 days versus > 7 days of symptom onset) using interaction tests. Among 70 included patients, 32 received interferon-ß1b and lopinavir-ritonavir and 38 received placebo. Interferon-ß1b and lopinavir-ritonavir reduced mortality in patients with lower IL-2, IL-8 and IL-13 plasma concentrations but not in patients with higher levels (p-value for interaction = 0.09, 0.07, and 0.05, respectively) and with early but not late therapy (p = 0.002). There was no statistically significant heterogeneity of treatment effect according to other cytokine levels. Further work is needed to evaluate whether the assessment of inflammatory status can help in identifying patients with MERS who may benefit from interferon-ß1b and lopinavir-ritonavir. Trial registration: This is a sub-study of the MIRACLE trial (ClinicalTrials.gov number, NCT02845843).

Favipiravir and Hydroxychloroquine Combination Therapy in Patients with Moderate to Severe COVID-19 (FACCT Trial): An Open-Label, Multicenter, Randomized, Controlled Trial.

INTRODUCTION: Antiviral drugs have shown limited effectiveness in treating patients with coronavirus disease 2019 (COVID-19). We aimed to assess the effects of a favipiravir and hydroxychloroquine combination on treating moderate-to-severe COVID-19 patients. METHODS: An investigator-initiated, multicenter, open-label, randomized trial at nine hospitals. Eligible patients were adults with moderate-to-severe COVID-19 defined as oxygen saturation (SaO2) of ≤ 94% while breathing ambient air or significant clinical symptoms with chest x-ray changes requiring hospital admission. Randomization was in a 1:1 ratio to receive standard care (control group) or standard care plus favipiravir and hydroxychloroquine. The primary outcome was time to clinical improvement of two points (from the status at randomization) on a seven-category ordinal scale or live discharge from the hospital within 14 days. Analyses were done in an intention-to-treat population. RESULTS: From May 2020 to Jan 2021, 254 patients were enrolled; 129 were assigned to standard of care and 125 to the treatment. The mean age was 52 (± 13) years, and 103 (41%) were women. At randomization, six patients were on invasive mechanical ventilation, 229 (90.15%) were requiring supplemental oxygen only (with or without non-invasive ventilation), and 19 (7.48%) were receiving neither. The time to clinical improvement was not significantly different between the groups: median of 9 days in the treatment group and 7 days in the control group (HR: 0.845; 95% CI 0.617-1.157; p-value = 0.29). The 28-day mortality was not significantly different between the groups (7.63% treatment) vs. (10.32% control); p-value = 0.45. The most prevalent adverse events were headache, elevation in ALT, and the prolonged QTc interval in the treatment group. CONCLUSION: The combination of favipiravir and hydroxychloroquine did not result in a statistically significant clinical benefit in patients with moderate-to-severe COVID-19. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT04392973).

A Trial of Favipiravir and Hydroxychloroquine combination in Adults Hospitalized with moderate and severe Covid-19: A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: The selected combination was based on limited evidence clinically and in vitro on the efficacy of the Favipiravir and Hydroxychloroquine in SARS-CoV-2. The two medications were listed in many guidelines as treatment options and ongoing trials assessing their efficacy and safety. Thus, we want to prove the clinical effectiveness of the combination as therapy. TRIAL DESIGN: This is an Open label, multicenter, randomized controlled clinical trial to evaluate the safety and efficacy of novel therapeutic agents in hospitalized adults diagnosed with COVID-19. It is a multicenter trial that will compare Favipiravir plus Hydroxychloroquine combination (experimental arm) to a control arm. PARTICIPANTS: All study procedures will be conducted in eight centres in Saudia Arabia: King Abdulaziz Medical City National Guard Health Affairs in Riyadh. King Abdulaziz Hospital - Al Ahsa, Saudi Arabia AlMadina General Hospital, Madnia, Saudi Arabia Al-Qatif Central Hospital, Saudi Arabia Imam Abdulrahman Al Faisal Hospital, Dammam, Saudi Arabia King Abdulaziz Medical City, Jeddah, Saudi Arabia King Abdulaziz Hospital, Makkah, Saudi Arabia Imam Abdulrahman Alfaisal Hospital, Riyadh, Saudi Arabia Inclusion Criteria • Should be at least 18 years of age, • Male or nonpregnant female, • Diagnosed with COVID-19 by PCR confirmed SARS-coV-2 viral infection. • Able to sign the consent form and agree to clinical samples collection (or their legal surrogates if subjects are or become unable to make informed decisions).. • Moderate or Severe COVID-19, defined as oxygen saturation (Sao2) of 94% or less while they were breathing ambient air or significant clinical symptoms that require hospital admission. • patients had to be enrolled within 10 days of disease onset. Exclusion Criteria • Patients who are pregnant or breastfeeding. • Will be transferred to a non-study site hospital or discharged from hospital within 72 hours. • Known sensitivity/allergy to hydroxychloroquine or Favipiravir • Current use of hydroxychloroquine for another indication • Prior diagnosis of retinopathy • Prior diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency • Major comorbidities increasing the risk of study drug including: i. Hematologic malignancy, ii. Advanced (stage 4-5) chronic kidney disease or dialysis therapy, iii. Known history of ventricular arrhythmias, iv. Current use of drugs that prolong the QT interval, Severe liver damage (Child-Pugh score ≥ C, AST> 5 times the upper limit), HIV. • The investigator believes that participating in the trial is not in the best interests of the patient, or the investigator considers unsuitable for enrollment (such as unpredictable risks or subject compliance issues). • Clinical prognostic non-survival, palliative care, or in deep coma and no have response to supportive treatment within three hours of admission • Patient with irregular rhythm • Patient with a history of heart attack (myocardial infarction) • Patient with a family history of sudden death from heart attack before the age of 50 • Take other drugs that can cause prolonged QT interval • Patient who is receiving immunosuppressive therapy (cyclosporin) which cannot be switched to another agent or adjusted while using the investigational drug • Gout/history of Gout or hyperuricemia (above the ULN), hereditary xanthinuria or xanthine calculi of the urinary tract. INTERVENTION AND COMPARATOR: The treatment intervention would be for a maximum of 10 days from randomization and it would be as follows: Favipiravir for 10 days: Administer 1800 mg (9 tablets) by mouth twice daily for one day, followed by 800mg (4 tablets) twice daily (total days of therapy is 10 days) Hydroxychloroquine for 5 days: (400mg) twice daily on day 1; for days 2-5 (200mg) twice daily. Reference Comparator Therapy: Standard of care is defined as: Treatment that is accepted by medical experts as a proper treatment for Covid-19 disease. Standard care comprised of, as necessary, supplemental oxygen, noninvasive and invasive ventilation, antibiotic agents, vasopressor support, renal-replacement therapy, extracorporeal membrane oxygenation (ECMO), and antiviral therapy except Favipiravir. Also, it may include intravenous fluids and medications for symptoms relief . MAIN OUTCOMES: The primary endpoint is the time to clinical improvement, defined as the time from randomization to an improvement of two points (from the status at randomization) on a seven-category ordinal scale or live discharge from the hospital, whichever came first (14 days from Randomization). RANDOMISATION: Eligible participants will be randomized in a 1:1 ratio to either the combination group (Favipiravir and Hydroxychloroquine) or a control group. The patients will be randomized utilizing Web based data entry System with a stratification based on the centre and the ICU admission. BLINDING (MASKING): This is an Open label study and only the analyst will be blinded during the study conduct. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): Under the classical two arm parallel design the total effective sample sizes needed is 472 subjects (236 subjects per group). TRIAL STATUS: Protocol version 3.1 (dated 11 Aug 2020), and currently recruitment is ongoing. The date recruitment started was May 21, 2020 and the investigators anticipate the trial will finish recruiting by the end of December 2020. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04392973 , 19 May 2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Interferon Beta-1b and Lopinavir-Ritonavir for Middle East Respiratory Syndrome.

BACKGROUND: Whether combined treatment with recombinant interferon beta-1b and lopinavir-ritonavir reduces mortality among patients hospitalized with Middle East respiratory syndrome (MERS) is unclear. METHODS: We conducted a randomized, adaptive, double-blind, placebo-controlled trial that enrolled patients at nine sites in Saudi Arabia. Hospitalized adults with laboratory-confirmed MERS were randomly assigned to receive recombinant interferon beta-1b plus lopinavir-ritonavir (intervention) or placebo for 14 days. The primary outcome was 90-day all-cause mortality, with a one-sided P-value threshold of 0.025. Prespecified subgroup analyses and safety analyses were conducted. Because of the pandemic of coronavirus disease 2019, the data and safety monitoring board requested an unplanned interim analysis and subsequently recommended the termination of enrollment and the reporting of the results. RESULTS: A total of 95 patients were enrolled; 43 patients were assigned to the intervention group and 52 to the placebo group. A total of 12 patients (28%) in the intervention group and 23 (44%) in the placebo group died by day 90. The analysis of the primary outcome, with accounting for the adaptive design, yielded a risk difference of -19 percentage points (upper boundary of the 97.5% confidence interval [CI], -3; one-sided P = 0.024). In a prespecified subgroup analysis, treatment within 7 days after symptom onset led to lower 90-day mortality than use of placebo (relative risk, 0.19; 95% CI, 0.05 to 0.75), whereas later treatment did not. Serious adverse events occurred in 4 patients (9%) in the intervention group and in 10 (19%) in the placebo group. CONCLUSIONS: A combination of recombinant interferon beta-1b and lopinavir-ritonavir led to lower mortality than placebo among patients who had been hospitalized with laboratory-confirmed MERS. The effect was greatest when treatment was started within 7 days after symptom onset. (Funded by the King Abdullah International Medical Research Center; MIRACLE ClinicalTrials.gov number, NCT02845843.).

Public motives and willingness to participate in first-in-human clinical trials in Saudi Arabia: A new era in the making.

BACKGROUND: Participation in first-in-human (FIH) clinical trials is a valuable contribution to science. This study aims to investigate the Saudi public's attitude toward FIH clinical trials, identify their willingness to take part in it, and their preferences for participating in these kinds of trials, given the fact that the Saudi FDA has never approved such studies in Saudi Arabia. METHODS: This was a cross sectional study conducted in February 2018. It was based on a self-reported survey distributed by convenience among Saudi adults visiting a national festival in Riyadh and through social media. Data were analysed using descriptive and bivariate statistics, as well as linear and binary logistic regression. RESULTS: Study participants who were invited and completed the survey were 657. The percentage mean score of participants' attitudes and concern was 70.1 ± 16.4 and 58.3 ± 15.3 respectively. Almost 71.5% expressed their intention to enroll in such trials. Higher attitudinal scores were reported by those who perceived healthcare services as good/excellent (adj.P < 0.001), and by those who had less concerns (adj.P = 0.005). Less educated participants were 1.75 [1.04-2.93] times more likely to enroll in future clinical trials, adj.P = 0.035. For every one unit increase in the attitudinal score, study participants were 1.03 [1.02-1.04] more likely to enroll in future trials, adj.P < 0.001. In contrary, for every one unit increase in concern scores, the odds of enrollment decreased among study participants by 0.98 [0.97-0.99], adj.P = 0.017. The factors causing people to decline participation were mainly fear of the unknown, social reasons, religious reasons, moral reasons, and the concern over human beings being treated as animals. The preferred duration for participation was 1-3 days (n = 268, 57%). Participants revealed their preferences of clinical trial studies were in favor: (a) vaccines (n = 209, 44.5%); (b) treatment drugs (n = 232, 49.4%); and (c) medical devices (n = 310, 66.0%). CONCLUSION: The Saudi public community showed a high level of enthusiasm for participation in future FIH clinical trials, yet they had some reservations. Increasing public awareness about the benefits of clinical trials and conduction process helps to alleviate the concerns of the Saudi people and to increase their likelihood of enrollment.