Browsing by Author "Grace, Andrews Nirmala"

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    Additive engineering for improving the stability of tin-based perovskite (FASnI3) solar cells
    (Elsevier, 2022-08-05) Li, Shaojie; Yang, Feng; Chen, Mengmeng; Yang, Jien; Jiang, Lulu; Sun, Yunjuan; Grace, Andrews Nirmala; Jain, Sagar M.; Liu, Hairui
    During the past few years, Tin (Sn)-based perovskites have been extensively investigated in the field of photovoltaics as promising candidates for new generation lead-free perovskite. Tin-based perovskites (ASnI3) present excellent photoelectric properties. However, there still remains a big concern over unsatisfactory stability. In reality, extensive efforts have been committed to improve the stability of perovskite active layer. In this review, a comprehensive understanding on defect formation, oxidation mechanism of Sn2+. Then, a detailed discussion on the recent advance the effect of additive engineering for the stability of FASnI3 PSCs, including antioxidants, 2D perovskite materials and functional passive molecular. Lastly, several key scientific issues and future research prospectives are proposed for achieving stable and high-performance Sn-based perovskite photovoltaics.
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    Dopants for enhanced performance of tin-based perovskite solar cells—a short review
    (MDPI, 2021-08-30) Liu, Hairui; Zhang, Zuhong; Yang, Feng; Yang, Jien; Grace, Andrews Nirmala; Li, Junming; Tripathi, Sapana; Jain, Sagar M.
    Lead-based perovskite solar cells had reached a bottleneck and demonstrated significant power conversion efficiency (PCE) growth matching the performance of traditional polycrystalline silicon solar cells. Lead-containing perovskite solar cell technology is on the verge of commercialization and has huge potential to replace silicon solar cells, but despite the very promising future of these perovskite solar cells, the presence of water-soluble toxic lead content is a growing concern in the scientific community and a major bottleneck for their commercialization. The less toxic, tin-based perovskite solar cells are promising alternatives for lead-free perovskite solar cells. Like lead-based perovskite, the general chemical formula composition of tin-based perovskite is ASnX3, where A is a cation and X is an anion (halogen). It is evident that tin-based perovskites, being less-toxic with excellent photoelectric properties, show respectable performance. Recently, numerous studies reported on the fabrication of Sn-based perovskite solar cells. However, the stability of this novel lead-free alternative material remains a big concern. One of the many ways to stabilize these solar cells includes addition of dopants. In this context, this article summarizes the most important fabrication routes employing dopants that have shown excellent stability for tin-based perovskite photovoltaics and elaborates the prospects of lead-free, tin based stable perovskite photovoltaics.
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    Performance evaluation of a low-cost, novel vanadium nitride xerogel (VNXG) as a platinum-free electrocatalyst for dye-sensitized solar cells
    (Royal Society of Chemistry, 2020-11-11) Gnanasekar, Subashini; Sonar, Prashant; Jain, Sagar M.; Jeong, Soon Kwan; Grace, Andrews Nirmala
    A vanadium nitride xerogel (VNXG) was synthesised by a simple and effective method of ammonialising a vanadium pentoxide xerogel at a higher temperature. Xerogel-structured materials possess salient features such as high surface area, tunable porosity and pore size that result in enhancing the catalytic activity by a fast electron-transport pathway and increase electrolyte diffusion channels. Metal nitrides are reported as promising alternate low-cost counter electrodes to replace the conventional and expensive platinum (Pt) counter electrode. Though few studies are reported on aerogel-based CEs for DSSCs, the present work is the first attempt to synthesize and evaluate the performance of xerogel-structured metal nitrides as counter electrode materials for dye-sensitized solar cells. The synthesized material was well characterized for its structural and morphological characteristics and chemical constituents by photoelectron spectroscopy. Finally, the VNXG was tested for its electrocatalytic performance as a choice of counter electrodes for dye-sensitized solar cells (DSSCs). The photo-current studies were performed under standard 1 SUN, class AAA-simulated illumination with AM1.5G. The consolidated results revealed that the vanadium nitride xerogel exhibited good photocatalytic activity and low charge transfer resistance. This identified it as a promising low-cost counter electrode (CE) material for dye-sensitized solar cells. The photo-current conversion efficiency of the vanadium nitride xerogel CE-based DSSC reached 5.94% comparable to that of the conventional thermal decomposed Pt CE-based DSSC, 7.38% with the same iodide/triiodide electrolyte system. Moreover, the 28 days stability study of VNXG CE DSSCs provided an appreciably stable performance with 37% decrement in the PCE under the same test condition.
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    Phosphorene, antimonene, silicene and siloxene based novel 2D electrode materials for supercapacitors - A brief review
    (Elsevier, 2022-01-21) Venkateshalu, Sandhya; Subashini, G.; Bhardwaj, Preetam; Jacob, George; Sellappan, Raja; Raghavan, Vimala; Jain, Sagar M.; Pandiaraj, Saravanan; Natarajan, Varagunapandiyan; Al Alwan, Basem Abdullah M.; Al Mesfer, Mohammed Khaloofah Mola; Alodhayb, Abdullah; Khalid, Mohamad; Grace, Andrews Nirmala
    In the past decade, 2D materials such as graphitic carbon nitride, transition metal dichalcogenides, layered metal oxides and hydroxides, hexagonal boron nitride and MXenes have garnered a great attention with the discovery of graphene. Very recently, novel 2D materials analogous to graphene such as phosphorene, antimonene, silicene, siloxene, germanene etc., were discovered and are emerging as strong competitors to the existing 2D materials. These materials pose explicit properties making them suitable for various applications. This article reviews the properties, synthesis techniques and the supercapacitive nature of phosphorene, antimonene, silicene and siloxene while briefing the properties of other 2D materials viz. germanene, stanene, arsenene and bismuthene. With the successful implementation of phosphorene as supercapacitor electrode, research is progressing in exploring the supercapacitive nature of other novel 2D materials. The investigations on these materials are still in its infancy and most of the properties lack experimental evidence. The current research trends on these novel materials are discussed in this review.