Doctoral Research
The complex nature of the interface necessitates a comprehensive understanding of the multitude of determining factors that contribute to its overall impact. Beginning from the synthesis, the structural characteristics depend upon the crystallisation kinetics giving rise to the formation of the interface. The phase distribution of 2D fragments onto/into 3D film, in turn, is influenced by the homogeneity of the organic spacer cations. Recent research has shown that large cations at 2D-on-3D interfaces are mobile.
Hence, absorber layer structure, if not appropriately studied, could lead to the induction of defect states unknowingly. Further, the photophysical properties such as absorption, emission and exciton dynamics depend upon the structural rigidity and interface integrity. One of the main challenges in studying heterostructures is to probe the interface between the different materials accurately. Often, researchers are limited to investigating only the 3D or 2D side of the heterostructure, which may not provide a complete picture of the properties and behaviour of the interface.
The focus of my research is the fabrication of efficient 3D-2D perovskite heterostructure-based devices. Initially, with extensive experimentation, the surface and bulk of 3D-perovskite will be studied at the nanoscale using imaging techniques and spectroscopic techniques. Finally, using the gained perspectives and output, 3D-2D perovskite-based devices being considered as the potential candidates for the development of unassisted solar water-splitting systems due to their extended durability, stability, and panchromatic absorption properties; the solar devices will be integrated with electrolyzers for hydrogen production.
Bachelors Research
During the penultimate year at IIT Delhi, I led a study investigating the effectiveness of self-similar aspects on the piezoresistive behaviour of carbon nanotubes on nonwoven structures in collaboration with Prof. Akos Kukovecz from the Department of Applied and Environmental Chemistry, University of Szeged.
A simple deformation mechanism of ‘functionalized-MWCNTs’ giving rise to the piezoresistive behaviour was proposed through four well-defined distinct regions. Region 1 offers low electrical resistance due to the high conductivity of the ‘f-MWCNTs’ and reveals the tunnelling effect under a low level of tensile loading. However, the reorientation quickly reaches the stalemate with the slippage generated between the ‘f-MWCNTs’, and accordingly, a slow rise in electrical resistance occurs in Region 2. On further stretching, there is a breakdown of connections between the CNTs as they slide past each other (Region 3). A subsequent rise in tensile load exceeds the shear strength between the CNTs, which ensures the infinite electrical resistance followed by the complete disintegration of the structure, as depicted in Region 4. [For more information, follow the link given below]
The work resulted in my first-authored publication, Structural Health Monitoring of Nonwoven Materials via self-similar Arrays of Carbon Nanotubes, published in Composites Communications (I.F = 8). Through the research, we have deconstructed the importance of MWCNTs as contenders in the field of self-similar, sensor-based materials via experimental validation.
Research Articles
Impact of Bending in Flexible Perovskite Solar Cells
Flexible perovskite solar cells (fPSCs) are considered promising for wearable and portable photovoltaic applications; however, their operational stability under mechanical stress remains a significant challenge. In this study, the degradation pathways of low-temperature-processed fPSCs fabricated on polyethylene terephthalate (PET)/ITO substrates using a SnO2/MAPbI3/Spiro-OMeTAD/Au architecture .....
Ultrafast Energy Transfer and Charge Transfer in Quasi-2D Perovskites
The efficient and rapid charge transfer at the interface of heterostructures plays a crucial role in optoelectronic applications. Quasi‐2D perovskites accompanying randomly dispersed various layer thickness (n) phases can introduce multiple interfaces with specific potential barriers, obstructing the charge transport and energy transfer processes. Herein, the strategic spatial distribution of various n phases and enhanced energy transfer, accompanied by the narrow‐band emission in the high n phases .......
Triplet Excitons in 2D Lead Halide Perovskites
The present work introduces a hybrid organic–inorganic 2D perovskite, where a rational molecular design strategy enables efficient triplet exciton generation through an excited-state energy transfer process. Upon photoexcitation, a sharp emission peak having a narrow bandwidth is observed at ∼400 nm, reflecting excitonic emission from the perovskite, which subsequently undergoes energy transfer to the energetically aligned triplet state of the organic spacer. The triplet state of the spacer molecule then undergoes radiative intersystem crossing .......
Doping Transition Metals in CuS
Copper Sulfide (CuS) semiconductors have garnered interest, but the effect of transition metal doping on charge carrier kinetics and bandgap remains unclear. In this study, the interactions between dopant atoms (Nickel, Cobalt, and Manganese) and the CuS lattice using spectroscopy and electrochemical analysis are explored. The findings show that sp‐d exchange interactions between band electrons and the dopant ions, which replace Cu2+, are key to altering the material's .......
Tuning TiO2 Phase and Morphology
The efficiency of mesoporous perovskite solar cells (mp-PSCs) is significantly influenced by favorable charge transport properties across their various interfaces. The interfaces involving compact-TiO2, mesoporous electron transport layer (ETL), and perovskite layer are particularly vital for high-performing devices. Our study presents a combined experimental and computational approach, specifically employing density functional theory, to explore the impact of mesoporous-ETL/perovskite interface properties on carrier transport .........
Interface Engineering 3D-2D Perovskite Solar Cells
In recent years, organic–inorganic metal halide perovskite solar cells (PSCs) have attracted considerable interest due to their remarkable and rapidly advancing efficiencies. Over the past decade, PSC efficiencies have significantly approached those of state-of-the-art silicon-based photovoltaics, making them a promising material. Currently, the scientific community widely recognizes the performance of 3D-PSCs and 2D-PSCs individually. However, when both are combined to form a heterostructure, the lattice and charge dynamics at the interface undergo a multitude of mechanisms ......
Structural Health Monitoring in Nonwovens
Unleashing the potential of self-similar materials could prove as serious contenders for next-generation sensors. Herein, a systematic approach to design and develop self-similar nonwoven interfacially aided with multi-walled carbon nanotubes (SS–NI-MWCNTs) via a facile, scalable, and cost-effective vacuum filtration process has been proposed. A simple deformation mechanism of SS-NI-MWCNTs giving rise to the piezoresistive behaviour has been correlated with the tensile mechanics universal to both nonwovens and random arrays of MWCNTs. The failure of the SS-NI-MWCNTs is preponderantly governed through inter-tube/fibre sliding that originates from self-similar serpentine characteristics ......