Publications

The recent advances in perovskite solar cells (PSCs) created a tsunami effect in the photovoltaic community. PSCs are newfangled high-performance photovoltaic devices with low cost that are solution processable for large-scale energy production. The power conversion efficiency (PCE) of such devices experienced an unprecedented increase from 3.8 % to a certified value exceeding 20 %, demonstrating exceptional properties of perovskites as solar cell materials. A key advancement in perovskite solar cells, compared with dye-sensitized solar cells, occurred with the replacement of liquid electrolytes with solid-state hole-transporting materials (HTMs) such as 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD), which contributed to enhanced PCE values and improved the cell stability. Following improvements in the perovskite crystallinity to produce a smooth, uniform morphology, the selective and efficient extraction of positive and negative charges in the device dictated the PCE of PSCs. In this Review, we focus mainly on the HTMs responsible for hole transport and extraction in PSCs, which is one of the essential components for efficient devices. Here, we describe the current state-of-the-art in molecular engineering of hole-transporting materials that are used in PSCs and highlight the requisites for market-viability of this technology. Finally, we include an outlook on molecular engineering of new functional HTMs for high efficiency PSCs.

Ceria nanoparticles with rhodamine B (RhB-CeNPs) are a new class of biocompatible nanomaterial with antioxidant activity and sensor capacity against oxidant species both in solution and in human cells.

In the present work, an attempt has been made to fabricate hybrid natural fiber composites, consisting of a poly-lactic-acid (PLA) matrix reinforced with jute and sisal fibers, using die molding process. The processing conditions of the hybrid composites, such as heating temperature, compression pressure, and final mold temperature, have been optimized in the response of the resulting tensile and flexural strength. The reinforced hybrid composites have been developed in accordance with the Taguchi L9-based design of experimentation, and statistical analysis has been performed to understand the significance of the selected input parameters. Furthermore, scanning electron microscopic (SEM) analysis of the fractured samples has been performed to observe the mechanisms of failure and adhesive characteristics. The statistical analysis highlighted that all input process parameters have significantly contributed to the resulting tensile and flexural strength at 95% confidence level.

Abstract Planar perovskite solar cells using low‐temperature atomic layer deposition (ALD) of the SnO 2 electron transporting layer (ETL), with excellent electron extraction and hole‐blocking ability, offer significant advantages compared with high‐temperature deposition methods. The optical, chemical, and electrical properties of the ALD SnO 2 layer and its influence on the device performance are investigated. It is found that surface passivation of SnO 2 is essential to reduce charge recombination at the perovskite and ETL interface and show that the fabricated planar perovskite solar cells exhibit high reproducibility, stability, and power conversion efficiency of 20%.

2-Hydroxy-1-naphthaldehyde based barbiturates were synthesized through an eco-friendly greener approach, by reaction of 2-hydroxynaphthalene-1-carbaldehyde with three different barbituric acid derivatives in presence of natural, biodegradable and biocompatible green catalyst chitosan-SO3H. The use of solvent-free reaction in presence of functionalized chitosan for the synthesis of barbituric acid derivatives makes the present protocol as green and eco-friendly. A comparative study of conventional as well as solvent-free methods highlights the advantages, such as admirable yield, reduced reaction time with eviction of environmentally hazardous solvents, which leads to sustainability. The chemical structures of compounds were characterized by spectral techniques like IR, 1H NMR, 13C NMR and mass spectrometry. Additionally, computational studies of synthesized compounds were performed using density functional theory (DFT) at M06 level and 6-311 G (d,p) basis set to elucidate the electronic structures, and counter check the experimental findings. Overall, DFT findings at M06/6-311G (d,p) level show good agreement with the experimental data which confirms the purity of entitled compounds. Natural bond orbital (NBO) analysis and non-linear optical (NLO) properties were explored at the M06-/6-311G (d,p) level of theory. NBO analysis confirmed that hyper conjugative interactions are responsible for the stability of compounds. The energy gaps in compounds 5, 6 and 7 were found as 3.822, 3.815 and 3.643 eV, respectively. Furthermore, the global reactivity parameters were calculated using the FMOs energies which indicate that 5–7 hold more donating capability and stability. NLO findings confirmed that 5–7 have superior properties as compared to prototype standard compounds which unveiled their potential applications for optoelectronic technology.

It is of significant importance for the design of electrodes to construct enhanced electrochemical sensing platforms, and a nanoarray offers an ideal architecture for the detection of molecules. In this communication, we demonstrate that cobalt phosphide nanowire array grown in situ on titanium mesh (CoP NA/TM) exhibits high catalytic activity towards electrooxidation of glucose. As a non-enzymatic electrochemical glucose sensor, this CoP NA/TM catalytic electrode possesses superior analytical performance with a short response time of less than 5 s, a wide linear range of 0.0005-1.5 mM, a low detection limit of 0.1 μM (S/N = 3), a high sensitivity of 5168.6 μA mM^-1 cm^-2, and a remarkable selectivity and long-term stability for glucose detection. We further demonstrate the successful use of such glucose biosensors in human blood serum and fruit juice.