Browsing by Author "Saykar, Nilesh G."

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A comprehensive review on defect passivation and gradient energy alignment strategies for highly efficient perovskite solar cells
(IOP Publishing Ltd, 2021-10-07T00:00:00) Saykar, Nilesh G.; Arya, Anil; Mahapatra, S.K.
Recent advances in photovoltaic devices demonstrate a potential candidature of the lead halide perovskite solar cells (PSCs) to fulfill the all-electric future of the world. Further improvements in efficiency and stability require minimization of non-radiative recombination arising due to the tr ap states created by the vacancies and defects. The device's performance is mostly determined by the perovskite absorber material, which has single-cation, mixed-cation, and/or mixed-halide composition-dependent optoelectronic capabilities. Herein, we present an insight on the state of the art of PSCs, including types of defects, their effects, and remedies of the same. Various design strategies administered to grow highly crystalline perovskite films with low defects at interfaces are described in detail. The inclusion of a few nm thin interlayer between perovskite and charge transport layer (CTL) is an effective way to passivate the defect at the interface. Furthermore, additive engineering is emerging as an excellent strategy to grow the defect-free perovskite by simply adding a polymer, ionic liquids, organic/inorganic salts in precursor solution without precipitating after film formation. The mitigation of charge recombination could be achieved by efficient charge extraction through proper energy alignment of CTLs and absorbers. Notably, we emphasize the interface, additive, and gradient band alignment engineering and resulting improvement in the photocurrent density, photovoltage, power conversion efficiency, and long-term stability. The present review gives complete information about PSCs, starting from the selection of the materials to PSC fabrication, charge carrier dynamics, defects, effects, and remedies. We hope that this summarised information will give a basic understanding of designing new passivation strategies for advancing PSC's present state of the art. � 2021 IOP Publishing Ltd.
High-performance supercapacitor based on MoS2@TiO2 composite for wide range temperature application
(Elsevier Ltd, 2021-06-07T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Arya, Anil; Banerjee, Indrani; Alegaonkar, Prashant S.; Mahapatra, S.K.
Transition metal sulphide and their composites gain attention as electrode material in energy storage devices due to their superior properties like excellent conductivity, high surface area, and porosity. We report an evaluation of the electrochemical performance of MoS2@TiO2 binary composite in symmetric supercapacitor assembly at different temperatures. A facile hydrothermal technique is used to prepare MoS2@TiO2 binary composite. Structural and morphological analysis reveals that highly crystalline composite comprising MoS2 assembled in flower-like flake configuration, whereas, TiO2 in nanorods form are prepared. Among all three electrodes, MoS2@15%TiO2 demonstrates maximum specific capacitance 210 F/g at 10 mV/s with excellent cycling stability (98%, 2000 cycles) at ambient temperature. It may be concluded that the mono-phased, mesoporous structure is a key feature behind the improved performance over the other electrodes. Further, improvement in charge-discharge characteristics has been observed by a factor of 200% at 60 �C attributing to low activation energy and faster ion dynamics at elevated temperatures. The impedance spectroscopic analysis reveals a significant reduction in interfacial impedances that leads to a superior capacitance effect compounded with favourable electrolytic charge dynamics. The highest energy density is reported to be 21 Wh/kg with a power density of 1300 W/kg in symmetric configuration. Synergistic effect of the binary system along with unique surface morphology and charge storage followed by intercalation and capacitive mechanism results in enhanced performance of supercapacitor with MoS2@15%TiO2. Thus, binary MoS2@TiO2 composite seems to be an exceptional candidate for the energy storage device operating at a wide temperature range (25�60 �C). � 2021 Elsevier B.V.
Microwave-Induced Rapid Synthesis of MoS2@Cellulose Composites as an Efficient Electrode Material for Quasi-Solid-State Supercapacitor Application
(John Wiley and Sons Inc, 2023-03-11T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Mahapatra, Santosh kumar
Transition-metal dichalcogenides (TMDs) are highly desired for energy-storage devices due to their intrinsic layered structure, huge surface area, and the large number of active sites. However, the TMDs fail to reach their potential due to restacking of 2D layered structures that remains a major technological hurdle. Herein, MoS2 nanosheets and cellulose fiber binary composite (MoS2@Cellulose) prepared by the microwave-assisted technique are demonstrated as an electrode material for supercapacitor application. The prepared material are tested in symmetric and asymmetric all solid-state device assemblies. It is found that the quasi-solid-state symmetric and quasi-solid-state asymmetric supercapacitors exhibited remarkably higher specific capacitance of ?294 and ?177 F g?1 at a current density of 1 A g?1, respectively, than their counterpart. Furthermore, the symmetric and asymmetric devices deliver excellent energy densities of ?40.84 and ?42.67 Wh kg?1 while maintaining the power density of 400 and 791.81 W kg?1, respectively, and outstanding cyclic stability. The cellulose entanglement causes a reduction in the aggregation and restacking of MoS2, which may improve the electrochemical performance of the supercapacitor. Herein this research, a pathway is provided to create an efficient energy-storage system using 2D materials with sustainable cellulose. � 2023 Wiley-VCH GmbH.
One-step hydrothermal synthesis of MoS2 nano-flowers CoS2 square composites electrode materials for supercapacitor application
(Elsevier Ltd, 2022-07-27T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Kumar Mahanta, Alok; Mahapatra, S.K.
Developing efficient materials for generating and storing renewable energy is now a pressing test for future energy demand. The advent of (2D) two-dimensional materials has attracted much research interest as electrode materials for supercapacitors due to their intriguing mechanical and electrochemical properties. This report used a facile one-step hydrothermal process to synthesize MoS2@CoS2 Composite as electrode materials for supercapacitors with good energy storage performance and explore energy generation and storage applications. The structure and morphology were investigated by X-ray diffraction pattern, field emission scanning electron microscope consisting of square-shaped CoS2 and flower-like MoS2, and characterization; meanwhile, their electrochemical properties were evaluated by CV, GCD, and EIS measurements. The electrochemical performance of symmetric MoS2@CoS2 binary Composite was examined in 1 M H2SO4 in a two-electrode assembly. The as-prepared MoS2@CoS2 electrode exhibited a specific capacitance of 199F/g at a current density of 2A/g, while its counterpart MoS2 electrode exhibited only 127F/g at 2 A/g current density. The MoS2@CoS2 composite attains specific energy and power densities of 27.74 WhKg?1 and 494.46 Wkg?1, respectively, due to the unique morphology of the MoS2-flowery shape and CoS2 square. CoS2 squares effectively prevent the agglomeration and restacking of MoS2 sheets, facilitating smother ion dynamics. Technological demonstration of MoS2@CoS2 cell is presented by illuminating commercially available light-emitting diode for more than 3 min. � 2022
Synergistic Effect of Crystallization Control and Defect Passivation Induced by a Multifunctional Primidone Additive for High-Performance Perovskite Solar Cells
(American Chemical Society, 2022-12-22T00:00:00) Saykar, Nilesh G.; Iqbal, Muzahir; Ray, Asim K.; Mahapatra, Santosh K.
The ionic nature of organic-inorganic metal halide perovskites endows intrinsic defects at the surface of the polycrystalline films. Simultaneous defect passivation during the growth of perovskite films could inhibit defect formation to a great extent. Herein, the anticonvulsant drug primidone (PRM) is demonstrated as a novel additive to control the crystallization and defect passivation of perovskites. The spectroscopic measurements support theoretical predictions showing the strong interaction between active functional groups and PbI2. An amount of PRM is tuned to obtain the perfect perovskite films with improved grain size and crystallinity than their control counterparts. Efficient PbI antisite defect passivation suppresses the non-radiative recombinations, resulting in higher luminance intensity and significantly longer charge carrier lifetimes. The PRM-modified perovskite solar cells (PSCs) show a power conversion efficiency (PCE) of 18.73%, much higher than that of control PSCs (16.62%). The ambient stability of PRM-modified PSCs is meritoriously increased compared to control PSCs. The PRM-modified PSCs show stability retention of up to 85% of the initial PCE after 1000 h, while control PSCs retain only 25% of the initial PCE after 550 h. The multifunctional defect passivation approach with the PRM additive shows the effective way for the efficiency and stability improvement of PSCs. � 2022 American Chemical Society.
Synergistically modified WS2@PANI binary nanocomposite-based all-solid-state symmetric supercapacitor with high energy density
(Royal Society of Chemistry, 2022-03-09T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Alegaonkar, Prashant S.; Mahapatra, Santosh K.
The rapid development of intelligent, wearable, compact electronic equipment has triggered the need for durable, flexible, and lightweight portable energy storage devices. Nanomaterials that are capable of delivering the high specific power density and commensurate energy density are potential candidate for realizing such devices. Herein, we report the facile synthesis of a binary nanocomposite WS2@PANI by utilizing hydrothermal and physical blending techniques to assess it as an electrode material for high-performance supercapacitors. The nanocomposite electrode delivered specific capacitance >335 F g?1 @ 10 mV s?1 (two-electrode), achieving energy and power densities of ?80 W h kg?1 and ?800 W kg?1, respectively, with capacitance retention of 83% even after 5000 charge-discharge cycles @ 10 A g?1, all of which are superior to the WS2 electrode. Dunns model quantifies capacitive and intercalative contributions that showed the cumulative effect of both to realize a robust, cost-effective, and energy-efficient device. The strategically incorporated PANI broadened the electrochemical window and the device's overall performance, resulting in high specific energy density. We demonstrated that our all-solid-state symmetric supercapacitor could be used to illuminate a light-emitting diode and drive a rotary motor. We believe that our WS2@PANI binary nanocomposite will be a potential candidate for energy storage devices. � 2022 The Royal Society of Chemistry