Perovskite solar cells (PSCs) have been reported to have a power conversion efficiency (PCE) of 27.3%, although their instability in enduring moisture, heat, and light is a major hindrance in energy-related applications. In this work, we investigate the role of La-doped BaSnO3 (LBSO) as an electron transport layer (ETL) to improve the aging performance of PSCs and its suitability with a fixed hole transport layer (HTL) and various absorber layers for PSCs. The first-principles calculations are performed on pristine BaSnO3 and LBSO using the full potential linear augmented plane wave (FPLAPW) method within a time-efficient orbital-independent modified Becke-Jhonson (mBJ) approach. The calculated results indicate that La doping results in BaSnO3 being an n-type semiconductor with electronic properties appropriate for its application as an efficient ETL for PSCs. The optical absorption and reflectivity spectra govern the superiority of LBSO over BaSnO3, and LBSO is found to transmit the solar photons in the perovskite absorber layer in a better way. The numerical simulations also authenticate LBSO as a more suitable ETL than BaSnO3 in the PSCs having prominent absorber layers, including MAPbI3, FAPbI3, CsPbI3, Cs x FA1-x PbI3, and MAPb(I1-x Cl x )3, where MA = CH3NH3 + and FA = CH(NH2)2 +, combined with the PTAA HTL.
This study presents the first bulk geochemical analysis of shale samples from the Upper Bhuban Formation near Tuirial in Saitual District, Mizoram, northeast India. The Hydrogen Index (HI) range from 33.33 to 95.65 mg HC/g TOC indicates that the studied shale contains type III-IV kerogen and is derived mainly from ligno-cellulosic organic matter mixed with oxidized plant debris. Low total organic carbon (0.20–0.33 wt
Inertial effects in magnetic relaxation dynamics remain an experimentally unexplored aspect of condensed matter systems with few examples reported in spin ice and ferrofluid compounds. In this work, we examine the relaxation dynamics in chiral magnet Co8Zn7Mn5 across magnetic phases. Conventional Debye and Cole-Cole models fail to capture the frequency dependence of ac susceptibility across different magnetic phases, whereas incorporating an inertial component successfully describes the dynamics thereby yielding a consistent relaxation time (tau) of 10-5 s for Co8Zn7Mn5. The field-dependent variation of tau exhibits a nonmonotonic nature, with the double-peak-like structure at the skyrmion phase transitions. Our results reveal the presence of inertial effect in magnetic relaxation behavior of beta-Mn type Co-Zn-Mn compounds. We demonstrate that the inertial effect is an intrinsic property of beta-Mn type Co-Zn-Mn compounds that is independent of any particular magnetic phase. We qualitatively argue that spin fluctuation is the most plausible cause for inertial effects in chiral magnets.
This study aims to examine the spatio-temporal patterns of the Universal Thermal Climate Index (UTCI) throughout the Indus, Ganges, and Brahmaputra (IGB) basins, adressing the crucial aspects of thermal discomfort that substantially affect human health, well-being, and work productivity. Thermal stress, induced by increasing temperature and humidity, poses significant public healthy risks, especially in highly populated and climatically vulnerable areas of the Himalayas. The UTCI provides comprehensive assessment of ambient thermal stress conditions by including climatic factors like air temperature, wind speed, humidity, and radiation. Monthly, seasonal, and annual varations and trends in UTCI were studied using ERA5-HEAT reanalysis data from 2000 to 2024. The findings indicate a statistically accelerated warming trend in the IGB region, characterised by different seasonal patterns and geographical variability. Notabally, significantly elevated UTCI trends (+ 1.00 to + 2.00 °C/decade) are evident in the Ganges basin, reflecting pronounced warming (MK p < 0.05) trends in the densely populated regions (390 persons/km²) of the IGB basins. UTCI category threshold indicate elevated heat stress conditions, additionally, UTCI based elevation regression analysis within the IGB basins revealed a substantial negative correlation (R2 = 0.94), with the lowlands of the Ganges basin experiencing the most heat stress. This highlights greater susceptibility in low-elevation, densely populated areas, particularly during the monsoon (R2 = 0.94) and pre-monsoon seasons (R2 = 0.92). There is a clear regional variability, with UTCI values gradually rising from the northeastern Himalayan areas to the southwestern alluvial zones, suggesting a directed increase in thermal stress throughout the IGB basin.
Semiconductor quantum dots (SQDs) are extensively used nanomaterial for sensing, electronics, drug delivery, and bioimaging. However, their poor aqueous solubility, lack of uniformity in synthesis, toxicity, and challenges in scalable fabrication frequently limit their applications. Carbon quantum dots (CDs) emerged as new safer alternatives to SQDs with comparable optical properties and diverse applications. Herein, fluorescent, biocompatible, and water-soluble, carbon dots were synthesized via cost-effective hydrothermal method using ascorbic acid (AA) as the sole precursor. The as-synthesized spherical 3-4 nm ascorbic acid-derived carbon dots (AA-CDs) exhibited maximum excitation at 340 nm, emission at 400 nm and displayed fluorescence quantum yield of similar to 29.89% with average fluorescence lifetime decay of similar to 1.12 ns. For technological domain, this study successfully formulated AA-CDs into anti-counterfeiting fluorescent ink that resembled conventional ink under visible light but exhibited bright blue fluorescence under UV excitation. Furthermore, AA-CDs displayed negligible toxicity toward both mycobacterial (e.g., Mycobacterium marinum) and mammalian (phorbol myristate acetate-treated human THP-1 macrophages) cells, supporting their safe applications in biomedicine. Rapid and efficient internalization of AA-CDs into M. marinum and THP-1 macrophage cells was evidenced by presence of bright blue fluorescence inside the cells, which highlighted their potential as nano-probe for real-time bioimaging and tracking cellular processes. Collectively, this study demonstrated AA-CDs as a proof-of-concept dual-function nanomaterial for applications across fluorescent ink-based security technology and nanomedicine.
