Rs Value Research Articles

Negative series resistance and photo-response properties of Au/PPY-MWCNTs composite/TiO2/Al2O3/n-Si/Al photodiode

The paper addresses a novel approach concerning the appearance of negative series resistance (Rs) at high frequencies for both temperatures and voltages. Most of the previous studies have focused on the relationship between voltage and current (I - V) to determine the value of Rs using several methods. By measuring capacitance and conductance as a function of voltage, we were able to develop a systematic analysis of series resistance. At high frequencies of 2 × 107, 107 Hz, Rs has negative values however, at frequency 106 Hz it takes both positive and negative values, whilst from (105 − 10) Hz it has positive values. Here in this article, we synthesized Au/PPY-MWCNTs/TiO2/Al2O3/n-Si/Al structure which can be used in a variety of applications such as supercapacitors, and diodes. We investigated the electrical properties such as ideality factor (n), barrier height (фb), series resistance using several approaches such as conventional, Chueng, and Nord methods. The structure has shown rectification with a good response to daylight illumination. The structure response to daylight illumination indicates that photodiodes have the potential to be used as solar detectors.

Investigation for mechanical properties of dissimilar friction stir welded joints of AA5083 and pure Cu

The invention of solid-state welding procedure assimilated as friction stir welding (FSW) has provided an opportunity for industry and scientists to join the non-weldable soft alloys with higher efficiency. FSW is a green and energy-efficient welding process that also makes it possible to weld dissimilar materials effectively with higher joint efficiency. Parameters of the process play an important role in deciding the effectiveness of the FSW process. The present work is an attempt to analyze the effects of rotational speed of tool (RS) on different mechanical characteristics of dissimilar FSWed joints of AA 5083 and pure copper. The RS was varied at three different levels i.e. 800, 1200 and 1600 RPM, where other parameters were kept constant. The results shows that mechanical strength is significantly affected by the variation of RS further, 1200 RPM was observed as optimum value of RS with maximum mechanical strength.

High efficiency and stable solid-state fiber dye-sensitized solar cells obtained using TiO2 photoanodes enhanced with metal organic frameworks

Solid-state fiber dye-sensitized solar cells (SS-FDSSCs) have been the subject of intensive attention and development in recent years. Although this field is only in its infancy, metal–organic frameworks (MOFs) are one such material that has been utilized to further improve the power conversion efficiency of solar cells. In this study, MOF-integrated DSSCs were shown to have potential in the development of solar cell devices with efficiency comparable to or better than that of conventional solar cells. The power conversion efficiency (PCE) of SS-FDSSCs was improved by embedding MOF-801 into a mesoporous-TiO2 (mp-TiO2) layer, which was used as a photoanode in SS-FDSSCs, which are inherently flexible. The PCE of the MOF-integrated SS-FDSSCs was 6.50%, which is comparable to that of the reference devices (4.19%). The MOF-801 enhanced SS-FDSSCs decreased the series resistance (Rs) value, resulting in effective electron extraction with improved short-circuit current density (JSC), while also increasing the shunt resistance (Rsh) value to prevent the recombination of photo-induced electrons. The result is an improved fill factor and, consequently, a higher value for the PCE.

Post annealing to improve the sheet resistance and uniformity of emitter for enhancing conversion efficiency of mass-produced mc-Si solar cells

The influence of annealing on the sheet resistance (Rs) and doping profile of P–N junction emitter and its correlation to the conversion efficiency of mass-produced mc-Si solar cells were investigated. It is found that the Rs of emitter increased reversely after annealing at a low temperature range of 650–750 °C, which differs from the conventional phenomenon that the Rs usually decreases with doping amount increasing during phosphorus (P) thermal diffusion process at a relatively high temperature. The doping profiles show that the shallow surface doping concentration was reduced significantly from 6.6 × 1021 cm−3 to 3.9 × 1021 cm−3 after annealing at 700 °C while the doping profile remained almost constant below the depth of 20 nm. The decreasing of surface doping concentration indicates that the P atoms distributed in the shallow surface of silicon should uphill-diffuse to the region near to phosphosilicate glass (PSG) layer, which reduces the total doping amount in emitter and consequently increases the Rs. For mass production, the average Rs was improved to ∼75 Ω/sq when the diffused silicon wafers with 66 Ω/sq emitter were annealed at 700 °C for 20 min, and moreover the Rs uniformity became better than that of the directly as-diffused silicon wafers with same level Rs value. Additionally, the solar cells exhibited a mean conversion efficiency of 18.63%, which was higher by 0.35% and 0.20% than those fabricated from the as-diffused silicon wafers with ∼66 Ω/sq and ∼75 Ω/sq emitter, respectively.

V2O5 Nanosheets as an Efficient, Low‐cost Pt‐free Alternate Counter Electrode for Dye‐Sensitized Solar Cells

AbstractThe search for cost‐effective and efficient counter electrode finds its way in choosing vanadium pentoxide, an abundant and low‐cost material with good electrocatalytic property and stability. Two‐dimensional vanadium pentoxide nanosheets (V2O5 NS) were prepared by a simple hydrothermal method followed by calcination at 350 °C. The morphology of the synthesized material provides an excellent surface property with good surface area and a wide range of porosity distribution helps in enhancing the electrocatalytic active sites for effective reduction of I3−. The electrochemical studies performed with V2O5 NS showed good electrocatalytic activity with high current density, low series and charge transfer resistance. The electrochemical techniques CV, EIS and Tafel polarization performed with V2O5 NS gave an enhanced electrocatalytic activity and charge transfer kinetics with a low value of Rs and Rct. Furthermore, the photocurrent voltage studies done with V2O5 NS CE DSSC achieved a PCE of 5.1% ( Open circuit voltage (Voc)=0.65 V, short ciruit photocurrent density (Jsc)=11.67 mA/cm2 and fill factor (FF)=66.46%) and the conventional thermal decomposed Pt CE DSSC reached the PCE of 7.4% (Open circuit voltage (Voc)=0.78 V, short circuit photocurrent density (Jsc)=15.03 mA/cm2 and fill factor (FF)=57.39%) under similar test conditions, appreciably good performance than previous reports on V2O5 CE DSSC. The present work encourages further extensive research to develop nanostructures of V2O5 as a low‐cost alternate counter electrode to Pt CE for large‐scale production.

Relationship Between Emotional Intelligence and Geography Learning Outcomes of Class XII Students at Wahdah Islamiyah Integrated Islamic High School Makassar

This study aims to determine whether there is a relationship between emotional intelligence and geography learning outcomes in class XII Islamic Senior High School Wahdah Islamiyah Makassar. This research is a type of quantitative research with the Spearman Rank correlation method. The data collection technique uses a questionnaire. The sampling technique in this study used a saturated sampling technique with a total of 25 respondents. For learning outcomes data is taken from the grade XII student report cards in the geography subject. The results of the analysis of emotional intelligence data are included in the medium category with an average value = 107.84 at intervals 103–110, for geography learning outcomes are included in the low category with an average value = 83.52 at intervals 81-84, to prove whether or not there is a relationship between emotional intelligence and geography learning outcomes, it can be seen from the calculation obtained using the Spearman Rank correlation formula, where the value of rs =0.037, with a significant value of 0.861. Because sig > 0.05, it can be concluded that emotional intelligence does not have a significant relationship with geography learning outcomes and the relationship is included in the very low category.

Thinning decreased soil respiration differently in two dryland Mediterranean forests with contrasted soil temperature and humidity regimes

The effects of a thinning treatment on soil respiration (Rs) were analysed in two dryland forest types with a Mediterranean climate in east Spain: a dry subhumid holm oak forest (Quercus ilex subsp. ballota) in La Hunde; a semiarid postfire regenerated Aleppo pine (Pinus halepensis) forest in Sierra Calderona. Two twin plots were established at each site: one was thinned and the other was the control. Rs, soil humidity and temperature were measured regularly in the field at nine points per plot distributed into three blocks along the slope for 3 years at HU and for 2 years at CA after forest treatment. Soil heterotrophic activity was measured in laboratory on soil samples obtained bimonthly from December 2012 to June 2013 at the HU site. Seasonal Rs distribution gave low values in winter, began to increase in spring before lowering as soil dried in summer. This scenario indicates that with a semiarid climate, soil respiration is controlled by both soil humidity and soil temperature. Throughout the study period, the mean Rs value in the HU C plot was 13% higher than at HU T, and was 26% higher at CA C than the corresponding CA T plot value, being the differences significantly higher in control plots during active growing periods. Soil microclimatic variables explain the biggest proportion of variability for Rs: soil temperature explained 24.1% of total variability for Rs in the dry subhumid forest; soil humidity accounted for 24.6% of total variability for Rs in the semiarid forest. As Mediterranean climates are characterised by wide interannual variability, Rs showed considerable variability over the years, which can mask the effect caused by thinning treatment.

Characterization of cosputtered NbTaMoW films

In this study, NbTaMoW medium-entropy alloy films were prepared using a cosputtering apparatus with four sputter guns. Pure-element targets were used for sputtering. The rotational speeds of the substrate holder (RS) were 1–30 rpm. Lower RS values resulted in the formed films exhibiting a multilayer stacked structure with a cyclical gradient concentration. The crystalline phases, mechanical properties, and oxidation behavior of the prepared NbTaMoW films were investigated. The uniformity of the prepared multilayered alloy films increased with the RS value. The monolithic NbTaMoW alloy films prepared at 30 rpm exhibited a single body-centered cubic (BCC) phase, hardness of 12.9 GPa, and Young's modulus of 278 GPa. The BCC phase evolved into a combination of multiple BCC phases when RS was <10 rpm. The multilayered NbTaMoW alloy films prepared at 10 rpm exhibited high hardness of 14.1 GPa and a comparable Young's modulus of 274 GPa. The prepared NbTaMoW films exhibited activation energy of 104 kJ/mol at 350–600 °C in air, and MoO3 was volatilized at temperatures of ≥550 °C. The monolithic and multilayered NbTaMoW films with a thickness of approximately 1240 nm were completely oxidized after annealing at 600 °C for 2 h.

Spatial non-stationarity effects of driving factors on soil respiration in an arid desert region

Soil respiration (Rs) has significant spatial changes in terrestrial ecosystems, especially in arid areas where ecological factors and vegetation distribution have obvious patches. Despite growing interest regarding the variation of Rs and its driving factors, most studies have ignored the spatial heterogeneity in the relationship between Rs and driving factors. Sampling plots (100 m × 100 m) were arranged along a vertical transect from the river including the three habitat types of river bank (RB), transitional zone (TZ), and desert margin (DM) in arid area of northwest China. The Rs, soil microclimate (soil temperature and soil water content), and soil nutrients of different habitats were synchronously monitored. Geostatistics and geographically weighted regression (GWR) methods were used to evaluate the spatial variability of Rs and its relationship with driving factors. The mean value of Rs in RB (0.29 ± 0.25 μmol m−2 s−1) was significantly higher than that in TZ (0.18 ± 0.10 μmol m−2 s−1) and DM (0.12 ± 0.11 μmol m−2 s−1). The degree of spatial dependence of Rs in RB was higher than that in TZ, and the spatial structure of Rs was not detected in DM. The GWR model can clearly reflect significant spatial differences in the effects of driving factors on Rs. Soil microclimate, total nitrogen, and soil pH had a strong influence on the spatial variation of Rs in RB. Soil microclimate, ammonium nitrogen, nitrate nitrogen, available phosphorus, and organic matter had strong effects on the spatial variation of Rs in TZ, and soil microclimate, total phosphorus, and organic matter had stronger effects on the spatial variation of Rs in DM. The results indicate that the GWR model can reveal the complex spatial relationship between Rs and driving factors in detail, and provide a new direction for exploring the spatial heterogeneity of Rs.

Role of ultrasound and magnetic resonance imaging in the prognosis and classification of muscle injuries in professional football players: correlation between imaging and return to sport time

PurposeTo study distractive muscle injuries applying US and MRI specific classifications and to find if any correlation exists between the results and the return to sport (RTS) time. The second purpose is to evaluate which classification has the best prognostic value and if the lesions extension correlates with the RTS time.MethodsA total of 26 male, professional soccer players (age 21.3 ± 5.6), diagnosed with traumatic muscle injury of the lower limbs, received ultrasound and MRI evaluation within 2 days from the trauma. Concordance between US and MRI findings was investigated. The relationships between MRI and US based injury grading scales and RTS time were evaluated. Correlation between injuries’ longitudinal extension and RTS time was also investigated.ResultsThe correlation between US and MRI measurements returned a Spearman value of rs = 0.61 (p = .001). Peetrons and Mueller-Wohlfahrt grading scales correlations with RTS time were r = 0.43 (p = .02) and r = 0.83 (p = < .001). The lesion’s extension correlation with RTS time was r = 0.63 (p < .001). The correlation between the site of the lesion and its location with the RTS time were rs = 0.2 and rs = 0.25.ConclusionsBoth US and MRI can be used as prognostic indicators along with the Peetrons (US) and the Mueller-Wohlfahrt (MRI) classifications. MRI is more precise and generates more reproducible results. The lesion craniocaudal extension must be considered as a prognostic indicator, while the injury location inside the muscle or along its major axis has doubtful significance.

Soil carbon dioxide effluxes from riparian areas of two hydrogeomorphic settings in the Ozark National Forest, USA

Riparian buffers serve as conduits through which carbon (C) cycles from terrestrial landscapes to aquatic systems and, ultimately, to oceanic or atmospheric sinks. Riparian areas have also been identified as zones of concentrated biogeochemical activity that often produce greater amounts of greenhouse gases than neighboring upland terrestrial and adjacent aquatic systems. Little work has explored how hydrologic classification of a stream may influence the magnitude of riparian soil processes. A three-way factorial field study examined soil carbon dioxide (CO2) effluxes across flow regime (Groundwater and Runoff streams), season (autumn, winter, spring, and summer), and distance from stream edge (0, 10, and 20 m). Soil CO2 efflux differed between flow regimes across seasons (P = 0.01), where Runoff sites had greater spring soil surface CO2 efflux (i.e., soil respiration mean ± 1 SE = 2.98 ± 0.29 μmol CO2 m−2 s−1) than Groundwater sites (1.40 ± 0.30 μmol CO2 m−2 s−1). Soil CO2 effluxes from Runoff sites were related to soil temperature (rs value range = 0.58 to 0.82, all P < 0.0001) and soil moisture (rs value range = −0.35 to 0.27, P = 0.02 to 0.03). However, effluxes were unrelated to soil moisture at Groundwater sites. Results of this study suggest that consideration of the riparian zone and demonstrated differences in flow regime are needed to understand forested stream C budgets. Anthropogenic landscape alteration and climate change can modify the natural flow regime which, in turn, may have consequences for aquatic C dynamics in streams draining altered riparian zones, particularly in forested settings.

Responses of soil respiration to rainfall depth and frequency in semiarid grassland communities

AbstractClimate change is increasing the extreme precipitation depth and frequency, which may cause a strong response of ecological processes in drought regions. To investigate how rainfall depth and frequency alter soil respiration (SR), a rainfall simulation experiment was conducted in grassland communities dominated by Artemisia gmelinii and Lespedeza davurica in Loess Plateau of China. SR rate (Rs), soil temperature (Ts) and soil volumetric water content (Sv) were monitored before and after the rainfall treatments, that is, four depths (5, 10, 20 and 40 mm) and three frequencies (40 mm × 1, 20 mm × 2 and 10 mm × 4) during the growing season (June to September). Results indicated that the response magnitude of Rs increased with rainfall depths, reaching the maximum under 40 mm, and the increments were tightly related to rainfall frequency and community type. The increase and mean value of Rs in A. gmelinii community were significantly higher than those in L. davurica and bare land under same rainfall depth. L. davurica community was more sensitive to rainfall lower than 10 mm, whereas it had weaker but longer response under rainfall larger than 10 mm compared with A. gmelinii community. Successive rainfall events dampened the pulse effect of Rs but generated more cumulative CO2 emission in vegetation communities. Ts and Sv varied significantly with rainfall depth and co‐regulated SR. These findings implied more CO2 will be released from soil in the semiarid grasslands under extreme and successive rainfalls and emphasized the importance of species impact on SR for soil carbon evaluation under future rainfall regimes.

Thymoquinone and its derivatives against breast cancer with HER2 positive: in silico studies of ADMET, docking and QSPR.

The high prevalence of HER2-positive breast cancer has become a significant concern in the health sector. The problem is more complex with the side effects of breast cancer drugs currently used. Thymoquinone (TQ), the main bioactive compound in Nigella sativa, has been shown to have anticancer activity. However, it is necessary to modify the structure of the thymoquinone derivatives to improve drug bioavailability. This study uses an in silico approach to predict pharmacokinetic profile, docking, quantitative structure-properties relationship (QSPR) of new thymoquinone-derived compounds as candidates cytotoxic agent for breast cancer with HER-2 positive. The prediction of ADMET was using pkCSM online. Molecular docking was used to determine thymoquinone derivatives activity using Molegro Virtual Docker version 5.5 by docking the thymoquinone derivatives to the HER2 receptor targets, PDB ID 3PP0 and QSPR analysis using the IBM SPSS 21 version. The 35 thymoquinone derivatives showed good physicochemical and absorption properties and not hepatotoxic, so they are suitable for oral drugs. The molecular docking of 35 thymoquinone derivatives against 3PP0 proteins showed better activity than thymoquinone. One of the thymoquinone derivatives, TQ 15, showed the largest negative RS value, meaning that is predicted to have the highest anticancer activity. Based on the QSPR analysis, the essential parameter in determining 35 thymoquinone derivatives activity was the lipophilic and steric parameter. Based on in silico test, thymoquinone derivative, TQ 15, had the potential to be further developed as a HER2-positive breast cancer drug.

Ag mesh network framework based nano composite for transparent conductive functional electrodes for capacitive touch sensor and thin film heater

We report on the development of a highly conductive, transparent and flexible Ag mesh-like network covered by an ITO/PEDOT:PSS nanocomposite for flexible conductive electronics. The electrode was deposited completely via solution-based deposition. A lower Rs value, from 7.21 Ω/□ to 5.05 Ω/□, was achieved by annealing the substrate via low-temperature plasma annealing. The low-temperature annealing was used to achieve crystallinity of the materials without deformation and degradation of PEDOT:PSS and the PET substrate. The low-cost deposition-based Ag NW-ITO/PEDOT:PSS electrode substantially decreased sheet resistance and provides the transmittance of 85.17%. The chemical stability and mechanical stability of the product were examined, and morphological studies were performed; in all of these, the substrate exhibited excellent behavior. Finally, a transparent flexible electrical heater and capacitive touch screen panel were fabricated using the Ag NW-ITO/PEDOT:PSS electrode to demonstrate the performance of the electrode and its potential applications.

Clinical profile and outcomes of patients with acute pancreatitis and correlation with severity index from a tertiary care centre in South India-retrospective analysis

Background: Acute pancreatitis is an inflammatory condition of the pancreas having a varied clinical presentation. It is one of the commonest causes of abdominal pain requiring hospital admission. This retrospective study aims to describe the clinical profile and outcomes of patients with acute pancreatitis and its correlation with severity index.Methods: All patients admitted with a diagnosis of acute pancreatitis to medical gastroenterology department between January 2018 to December 2020 were included in this retrospective study.Results: A total of 61 subjects were included in the final analysis. The mean age was 41.64, the ranged between 19 to 88 years. Among the study population, 53 (86.89%) were male and 8 (13.11%) were female. Among the people 43 (70.49%) were alcoholics, 22 (36.07%) were smokers, 11(18.03%) had systemic hypertension and 5 (8.20%) participants had type 2 diabetic mellitus. The mean CTSI was 2.15±2.82, the mean Balthazar was 3.43±2.4 and the mean procalcitonin was 2.52±9.28. The mean Lipase was 7822. There was a weak positive correlation between CTSI and CRP (rs value: 0.147, p=0.260). There was a weak negative correlation between Balthazar and CRP (rs value:-0.067, p=0.606).Conclusions: Among the study population, 87% of the patients were males. 70% of the population were alcoholics. Mean serum lipase was 7822. There was a weak positive correlation between CTSI and CRP (rs value: 0.147, p=0.260). There was a weak negative correlation between Balthazar and CRP (rs value:-0.067, p=0.606).

Comparing practice patterns and outcomes for early-stage hormone receptor-positive and node-positive breast cancer patients with high-intermediate-risk Oncotype Dx scores in the National Cancer Database.

e12520 Background: Oncotype Dx (ODX) is a commercial diagnostic test primarily used to predict the likely benefit from chemotherapy in ER+, HER2-, and node negative breast cancer. The prognostic value (recurrence risk) has also been demonstrated to apply to early stage lymph node positive (LN+) disease in a number of retrospective and prospective studies. The ongoing RxPONDER trial aims to clarify the predictive value of RS in LN+ population. In light of the initial results, we analyzed the practice patterns and outcomes for HR+/Her2 -/node positive breast cancer patients receiving ODX testing in the years from 2010-2017 with RS 14-25 in a retrospective observational study of the NCDB. Methods: Women with HR+/Her2 -/node positive breast cancer receiving ODX testing from 2010-2017 were identified in the NCDB using TAILORx and RxPONDER patients’ inclusion criteria: ages 18-75, 6-50mm invasive tumors, N1, M0, ER+/HER2 -. The impact of ODX results in the high-intermediate range (14-25) and other clinico-pathologic variables on the receipt of chemotherapy were compared. Additionally, we examined the impact of chemotherapy on overall survival (OS). Frequencies, Kaplain-Meier analysis, and changepoint analysis using the Contal and O’Quigley method were utilized. Results: There were 109,652 T1-2 and N1 patients of whom 32,506 (29.6%) received ODX testing. 13,461 (41.4%%) women had scores in the high-intermediate (14-25) range. The majority tended to have only 1 LN involved (1LN: 77.2%, 2LNs: 17.5%, 3LNs: 5.3%), had a mean age of 57.8y, were Caucasian (86.4%), and were preferentially tested at academic or comprehensive community cancer programs (79.2%). 6,610 (49.3%) patients were recommended chemotherapy, the median ODX score for all women who were recommended chemotherapy was 20 compared to 17 for those whom chemotherapy was not recommended. 5,068 (76.7%) women had documentation of receiving chemotherapy which correlated with improved OS regardless of age. Conclusions: In the group of women with HR+/Her2 -/node positive breast cancer, clinicians appear to utilize ODX testing in less than one-third of patients, possibly finding RS to be most useful in guiding adjuvant therapy recommendations when only 1LN is involved. Both the recommendation and receipt of chemotherapy correlated linearly with increasing RS, as expected based on the current NCCN guideline recommendations. We identified an OS benefit when chemotherapy was administered, regardless of patient age. Long-term follow-up in the RxPONDER trial will likely continue to clarify the predictive value of RS &lt; 25 in the ER+/HER2-/node positive breast cancer population.

Structure Modifications of Pinostrobin from Temu Kunci (Boesenbergia pandurata ROXB. SCHLECHT) and Their Analgesic Activity Based on in Silico Studies

Temu kunci (Boesenbergia pandurata ROXB. SCHLECHT) is one of Indonesia medicinal plants which contains essential oils and flavonoids and it has interesting pharmacological activities, such as antifungal, antibacterial, antioxidant, anti-inflammatory and anti-cancer. It also contains pinostrobin which potent as anti-inflammatory and analgesic activities through inhibition of COX-2 enzymes. This research was to obtain pinostrobin derivatives of acylation reactions between pinostrobin and acyl chloride derivatives. The structure modifications of pinostrobin were obtained by Schotten-Baumann method through nucleophilic substitution reactions between pinostrobin and acyl chloride derivatives. Their structure had analyzed using the spectrophotometric analysis (NMR, IR, and GC/MS). The investigation of structure modifications of pinostrobin (1) from this plant has demonstrated the presence of pinostrobin acetate (2) and new pinostrobin propionate (3). The 2 and 3 are derivatives of pinostrobin that can be synthesized using the Schotten-Baumann method to yield 84.3% and 73.9%, respectively. The results of in silico study between pinostrobin and pinostrobin acyl derivatives on the COX-2 receptor with a PDB code: 1PXX showed that pinostrobin RS value was -87.18kcal/mol, while pinostrobin propionate had a RS value of -98.61 kcal/mol. It can be predicted that the pinostrobin acyl derivative has greater analgesic activity than pinostrobin, so it is feasible to be developed and carried out research on its analgesic activity in vivo.

Study on the series resistance of crystal violet dye-based organic photovoltaic device in presence of single walled carbon nanotubes

The series resistance (Rs) of any organic photovoltaic device (OPV) plays an important role on the device performance. Generally, the electrode and the presence of traps at the interface contribute the high Rs. In this present work, we have studied the Rs of crystal violet dye-based OPV device and its variation in the presence of single walled carbon nanotubes (SWCNT). From the dark current voltage (I–V) characteristics, we have extracted Rs by using the Cheung–Cheung method. It is observed that the trap energy (Ec) and the value of Rs are decreased in the presence of SWCNT. The values of Rs and Ec are about 0.246 MΩ and 0.085 eV in the absence of SWCNT and these values change to 0.124 MΩ and 0.060 eV, respectively, in the presence of SWCNT. The light I–V characteristics of the devices have also been studied to find out the Rs of the device under illumination. Under illumination, the charge transport process is governed by the incident photon energy (Em) which is absorbed by the OPV device. So we have extracted the Em from the light I–V characteristics and estimated the Rs by using area method under light illumination in the absence and presence of SWCNT. It is observed that the extracted values of Rs under illumination are low compared to the values of Rs measured from dark I-V characteristics.

Impact of Photoluminescence Reabsorption in Metal‐Halide Perovskite Solar Cells

The precise quantification of the impact of photoluminescence reabsorption (PLr) in metal‐halide perovskite solar cells (PSCs) remains challenging. Herein, the PLr effect is examined by combined time‐resolved photoluminescence (TRPL) spectroscopy and time‐resolved terahertz spectroscopy (TRTS) and a model is proposed that relates both, the PLr and nonradiative recombination rate (knr) to the quasi‐Fermi‐level splitting (QFLS). PLr is shown to be beneficial for QFLS when the nonradiative recombination rate (knr) is below a critical value of ≈7 × 105 s−1; at high knr PLr is detrimental to QFLS. By incorporating PLr into a two‐diode model that allows extraction of the effective knr, the series resistance (rs), and the shunt resistance (rsh) in PSCs, it is found that neglecting PLr overestimates the effective knr, although it does not affect the value of rs and rsh. The findings herein provide insight into the impact of the PLr effect on metal‐halide PSCs.

Effects of Thallium–Aluminum‐Codoped Zinc Oxide Thin Film as a New Transparent Conducting Oxide

Herein, the electro–optical properties of sol–gel spin‐coated “thallium–aluminum‐codoped zinc oxide (TAZO)” focusing on the effects of thallium are investigated. It is shown that the amount of thallium (Tl) has a significant effect on improving the electrical properties of TAZO as a new transparent conducting oxide (TCO). The optimum results are achieved by adding 1 at% of Tl to aluminum‐doped zinc oxide (AZO), after which the sheet resistance (Rs) value is reduced from 30.21 to 2.832 KΩ sq−1. Although less Rs is recorded in all amounts of Tl used (from 1 to 4 at%) than in Tl‐free samples, Rs also increases as the amount of Tl increases, which is related to the degradation of the crystal structure at higher values of Tl. In view of a trade‐off between electrical conductivity and optical transparency, a decrease in transparency in the presence of Tl is a predictable issue, but while the Tl‐free samples record 90% transparency, the uniform thin film of 1 at% Tl‐AZO is able to achieve 85% transparency. This small amount of reduction in transparency shows the high potential of Tl to improve the properties of AZO as a TCO.