Oindrila Halder | Indian Association for the Cultivation of Science (original) (raw)

Papers by Oindrila Halder

Nucleation and Atmospheric Aerosols, 2018

Cadmium selenide (CdSe) nanomaterial of different shape and sizes has been considered as a suitab... more Cadmium selenide (CdSe) nanomaterial of different shape and sizes has been considered as a suitable material in optoelectronics, lasing devices and sensoric applications. Moreover, the increasing technological demands propose the improvement of their performance. One of theapproach towards controlling the properties is, through doping transition metals. Interestingly, Manganese (Mn) doping introducesspin degrees of freedom into the electronic structure of the CdSeyielding improvedoptical and magnetic properties for accomplishment of next generationopto-spintronics and memory devices. This coexistence of tunablemagnetic and optical properties aspires to this current work where we have synthesized and optimized the Mn doping in ultrathin (thickness 1.5nm) CdSe layered nanosheets (LNS) by a scaffold mediated solvothermal technique. Themagnetic and photoluminescence propertiesexhibitedspin allowed radiative transitionsin comparison with un-doped CdSe LNSs. The schematic of spin-active states rendering selective optical and magnetic properties are shown in Fig. 1.Cadmium selenide (CdSe) nanomaterial of different shape and sizes has been considered as a suitable material in optoelectronics, lasing devices and sensoric applications. Moreover, the increasing technological demands propose the improvement of their performance. One of theapproach towards controlling the properties is, through doping transition metals. Interestingly, Manganese (Mn) doping introducesspin degrees of freedom into the electronic structure of the CdSeyielding improvedoptical and magnetic properties for accomplishment of next generationopto-spintronics and memory devices. This coexistence of tunablemagnetic and optical properties aspires to this current work where we have synthesized and optimized the Mn doping in ultrathin (thickness 1.5nm) CdSe layered nanosheets (LNS) by a scaffold mediated solvothermal technique. Themagnetic and photoluminescence propertiesexhibitedspin allowed radiative transitionsin comparison with un-doped CdSe LNSs. The schematic of spin-active states rendering selecti...

DAE SOLID STATE PHYSICS SYMPOSIUM 2016, 2017

The trend of tuning transitional materials in semiconductors is advancing everyday research. The ... more The trend of tuning transitional materials in semiconductors is advancing everyday research. The composite behavior exhibited by doped nanoparticles is governed by many factors. These can either improve or adversely affect the desired electronic properties. In this work we have compared the Raman Scattering study of different power dependent excitations on CdSe nanosheets and manganese doped CdSe nanosheets and delved into the possibilities of their different electronic structures due to the phonon contribution.

Nanoscale advances, 2022

A key aspect of the use of conventional fabrics as smart textiles and wearable electronics is to ... more A key aspect of the use of conventional fabrics as smart textiles and wearable electronics is to incorporate a means of electrical conductivity into single polymer fibres. We present the transformation of thin polymer fibres and fabrics into conductive materials by in situ growth of a thin, optically transparent gold-silver nanowire (NW) mesh with a relatively low metal loading directly on the surface of polymer fibres. Demonstrating the method on poly(lactic-co-glycolic) acid and nylon microfibres, we show that the NW network morphology depends on the diameter of the polymer fibres, where at small diameters (1-2 mm), the NWs form a randomly oriented network, but for diameters above several micrometers, the NWs wrap around the fibres transversally. This phenomenon is associated with the stiffness of the surfactant templates used for the NW formation. The NW-decorated fibres exhibit a significant increase in conductivity. Moreover, single fibres can be stretched up to $15% before losing the electrical conductivity, while non-woven meshes could be stretched by about 25% before losing the conductivity. We believe that the approach demonstrated here can be extended to other polymeric fibres and that these flexible and transparent metal-coated polymer fibres could be useful for various smart electronic textile applications.

Nanotechnology, May 19, 2021

The exciton properties of (Cd,Mn)Se-NrGO (nitrogen doped reduced graphene oxide) hybrid layered n... more The exciton properties of (Cd,Mn)Se-NrGO (nitrogen doped reduced graphene oxide) hybrid layered nanosheets have been studied in a magnetic field up to 10 T and compared to those of (Cd,Mn)Se nanosheets. The temperature dependent photoluminescence reveals the hybridization of inter-band exciton and intra-center Mn transition with enhancement of the binding energy of exciton-Mn hybridized state (80 meV with respect to 60 meV in (Cd,Mn)Se nanosheets) and increase of exciton—phonon coupling strength to 90 meV (with respect to 55 meV in (Cd,Mn)Se nanosheets). The circularly polarized magneto—photoluminescence at 2 K provides evidence for magnetic field induced exciton spin polarization and the realization of excitonic giant Zeeman splitting with g eff as high as 165.4 ± 10.3, much larger than in the case of (Cd,Mn)Se nanosheets (63.9 ± 6.6), promising for implementation in spin active semiconductor devices.

Applied Physics Letters, May 5, 2014

RSC Advances, 2015

The solution-based assembly of h-Au8 clusters into a local periodic structure (LPS) of periodicit... more The solution-based assembly of h-Au8 clusters into a local periodic structure (LPS) of periodicity 1.47 nm with negative chirality as confirmed by experimental and theoretical analyses exhibits excitonic couplet state.

Nanotechnology, Nov 10, 2016

Gold cluster (Au8) coated CdS hybrid nanorods (HNRs), synthesized using a sonication assisted ass... more Gold cluster (Au8) coated CdS hybrid nanorods (HNRs), synthesized using a sonication assisted assembly route, exhibit phonon assisted coherent mixing of excitons. As observed from optical absorption, Raman scattering, x-ray diffraction and transmission electron microscopic studies, the Au8 modulates the crystal-and electronic-structure of the CdS nanorods, effecting enhancement of exciton-phonon (e-p) interactions. The e-p interaction and entropy effect mediated phase matching of the excitonic transitions, leading-via cooperative and coherent mixing of the excitons' color-to the emission of white light, has been confirmed from room temperature and time resolved photoluminescence measurements.

Scientific Reports, 2019

The layered nanosheets exhibit a variety of physical and optical properties originating from amal... more The layered nanosheets exhibit a variety of physical and optical properties originating from amalgamation of intra- and inter- layer electronic interactions, which makes them promising materials for advanced devices with varsatile controlling channels. In particular, the dilute magnetic semiconductor multilayered nanosheets have promising optical, electrical and magnetic properties that have been less explored so far. Here, the spin permissible optical properties from solvothermally grown Mn doped CdSe (thickness ~2.26 nm) multilayered nanosheets are reported on. The presence of multi-phase magnetic orderings with a sharp ferromagnetic transition at temperature ~48 K pertinent to the stabilization and co-existence of Mn2+and Mn3+based local phases have been observed from the (Cd,Mn)Se layered nanosheets corroborating to the x-ray absorption near edge structure, electron paramagnetic resonance, Raman scattering and magnetic measurements. The optical absorption and photoluminescence (...

RSC Adv., 2015

Scientific Reports

the layered nanosheets exhibit a variety of physical and optical properties originating from amal... more the layered nanosheets exhibit a variety of physical and optical properties originating from amalgamation of intra-and inter-layer electronic interactions, which makes them promising materials for advanced devices with varsatile controlling channels. In particular, the dilute magnetic semiconductor multilayered nanosheets have promising optical, electrical and magnetic properties that have been less explored so far. Here, the spin permissible optical properties from solvothermally grown Mn doped CdSe (thickness ~2.26 nm) multilayered nanosheets are reported on. The presence of multi-phase magnetic orderings with a sharp ferromagnetic transition at temperature ~48 K pertinent to the stabilization and coexistence of Mn 2+ and Mn 3+ based local phases have been observed from the (Cd,Mn)Se layered nanosheets corroborating to the x-ray absorption near edge structure, electron paramagnetic resonance, Raman scattering and magnetic measurements. the optical absorption and photoluminescence (PL) studies at room temperature affirm wide array of optical properties in the visible regime corresponding to the band edge and intriguing dopant-phase mediated spin approved transitions. The circularly polarized magneto-PL and life time analysis exhibits the spin-polarized fast radiative transitions confirming the presence of spin-active electronic states. The two-dimensional (2D) semiconductors 1 and doping effect in its layered structures are an active domain of research to offer advanced optical 2 , conductive 3 and magnetic properties 4,5 as a prospect of new generation device applications. Simultaneously, no effective methods of enhancing the sensitivity of these materials with reference to the external field has been established so far. Skillful doping of transition metal ions in nanostructures alter their spin degrees of freedom with promising giant Zeeman splitting 3,6 , magneto-optical 7 and fast spin-lattice dynamics 8. For instance, it activates a long range magnetic ordering crucial for spin-photonics 9 , spintronics 10 and carrier-induced magnetism 5. Moreover, the reports on doping manganese (Mn) ions are currently establishing the coexsistance of Mn 2+ /Mn 3+ states leading to various interactions and spin-allowed transitions 11. In particular to Mn doped bulk cadmium selenide ((Cd,Mn)Se), antiferromagnetism is stereotype 1,12,13 due to the short range d-d interactions. However, the calculations predict hole-induced long range ferromagnetism (FM) from nanocluster state or co-doping 14,15. Besides this, M. Sawicki et al. 16 , G. L. Gutsev et al. 14,17,18 and J. Yang 19 expressed intriguing magnetic states and related spin-active optical properties depending upon the concentration and ionic coordinations of the dopant. Similarly, the optical studies of a very low Mn doped CdSe/ZnSe core-shell quantum dots 20,21 predicts insignificant role of an individual Mn 2+ on the properties of host lattice. Nevertheless, studies on different quantum structures report on quenchning and shifting 22 of optical properties with the Mn 2+ state. Despite of the low solubility, several groups have initiated the Mn doping in various structure and composition 23-25 regardless of the ordinary properties. However, the concerns over doping stabilization in multilayered nanostuctures and its correlated properties orginating from intra-layer and inter-layer connected electronic states are yet to be explored. In this work, we report on (i) the successful doping of Mn into the cadmium selenide (CdSe) multilayered nanosheets (LNSs) lattice using a solvothermal route, (ii) strain induced stabilization and co-exitance of Mn 2+ / Mn 3+ states leading to multi-phase magnetic ordering with sharp ferromagnetic ordering at temperature ~48 K,

Nanoscale Advances

Nanotechnology, 2021

Scientific Reports, 2019

the layered nanosheets exhibit a variety of physical and optical properties originating from amal... more the layered nanosheets exhibit a variety of physical and optical properties originating from amalgamation of intra-and inter-layer electronic interactions, which makes them promising materials for advanced devices with varsatile controlling channels. In particular, the dilute magnetic semiconductor multilayered nanosheets have promising optical, electrical and magnetic properties that have been less explored so far. Here, the spin permissible optical properties from solvothermally grown Mn doped CdSe (thickness ~2.26 nm) multilayered nanosheets are reported on. The presence of multi-phase magnetic orderings with a sharp ferromagnetic transition at temperature ~48 K pertinent to the stabilization and coexistence of Mn 2+ and Mn 3+ based local phases have been observed from the (Cd,Mn)Se layered nanosheets corroborating to the x-ray absorption near edge structure, electron paramagnetic resonance, Raman scattering and magnetic measurements. the optical absorption and photoluminescence (PL) studies at room temperature affirm wide array of optical properties in the visible regime corresponding to the band edge and intriguing dopant-phase mediated spin approved transitions. The circularly polarized magneto-PL and life time analysis exhibits the spin-polarized fast radiative transitions confirming the presence of spin-active electronic states. The two-dimensional (2D) semiconductors 1 and doping effect in its layered structures are an active domain of research to offer advanced optical 2 , conductive 3 and magnetic properties 4,5 as a prospect of new generation device applications. Simultaneously, no effective methods of enhancing the sensitivity of these materials with reference to the external field has been established so far. Skillful doping of transition metal ions in nanostructures alter their spin degrees of freedom with promising giant Zeeman splitting 3,6 , magneto-optical 7 and fast spin-lattice dynamics 8. For instance, it activates a long range magnetic ordering crucial for spin-photonics 9 , spintronics 10 and carrier-induced magnetism 5. Moreover, the reports on doping manganese (Mn) ions are currently establishing the coexsistance of Mn 2+ /Mn 3+ states leading to various interactions and spin-allowed transitions 11. In particular to Mn doped bulk cadmium selenide ((Cd,Mn)Se), antiferromagnetism is stereotype 1,12,13 due to the short range d-d interactions. However, the calculations predict hole-induced long range ferromagnetism (FM) from nano-cluster state or co-doping 14,15. Besides this, M. Sawicki et al. 16 , G. L. Gutsev et al. 14,17,18 and J. Yang 19 expressed intriguing magnetic states and related spin-active optical properties depending upon the concentration and ionic coordinations of the dopant. Similarly, the optical studies of a very low Mn doped CdSe/ZnSe core-shell quantum dots 20,21 predicts insignificant role of an individual Mn 2+ on the properties of host lattice. Nevertheless, studies on different quantum structures report on quenchning and shifting 22 of optical properties with the Mn 2+ state. Despite of the low solubility, several groups have initiated the Mn doping in various structure and composition 23-25 regardless of the ordinary properties. However, the concerns over doping stabilization in multilayered nanostuctures and its correlated properties orginating from intra-layer and inter-layer connected electronic states are yet to be explored. In this work, we report on (i) the successful doping of Mn into the cadmium selenide (CdSe) multilayered nanosheets (LNSs) lattice using a solvothermal route, (ii) strain induced stabilization and co-exitance of Mn 2+ / Mn 3+ states leading to multi-phase magnetic ordering with sharp ferromagnetic ordering at temperature ~48 K,

Highly luminescent two dimensional excitons in atomically thin CdSe nanosheets

Nucleation and Atmospheric Aerosols, 2018

DAE SOLID STATE PHYSICS SYMPOSIUM 2016, 2017

Nanoscale advances, 2022

Nanotechnology, May 19, 2021

Applied Physics Letters, May 5, 2014

RSC Advances, 2015

Nanotechnology, Nov 10, 2016

Scientific Reports, 2019

RSC Adv., 2015

Scientific Reports

Nanoscale Advances

Nanotechnology, 2021

Scientific Reports, 2019

the layered nanosheets exhibit a variety of physical and optical properties originating from amal... more the layered nanosheets exhibit a variety of physical and optical properties originating from amalgamation of intra-and inter-layer electronic interactions, which makes them promising materials for advanced devices with varsatile controlling channels. In particular, the dilute magnetic semiconductor multilayered nanosheets have promising optical, electrical and magnetic properties that have been less explored so far. Here, the spin permissible optical properties from solvothermally grown Mn doped CdSe (thickness ~2.26 nm) multilayered nanosheets are reported on. The presence of multi-phase magnetic orderings with a sharp ferromagnetic transition at temperature ~48 K pertinent to the stabilization and coexistence of Mn 2+ and Mn 3+ based local phases have been observed from the (Cd,Mn)Se layered nanosheets corroborating to the x-ray absorption near edge structure, electron paramagnetic resonance, Raman scattering and magnetic measurements. the optical absorption and photoluminescence (PL) studies at room temperature affirm wide array of optical properties in the visible regime corresponding to the band edge and intriguing dopant-phase mediated spin approved transitions. The circularly polarized magneto-PL and life time analysis exhibits the spin-polarized fast radiative transitions confirming the presence of spin-active electronic states. The two-dimensional (2D) semiconductors 1 and doping effect in its layered structures are an active domain of research to offer advanced optical 2 , conductive 3 and magnetic properties 4,5 as a prospect of new generation device applications. Simultaneously, no effective methods of enhancing the sensitivity of these materials with reference to the external field has been established so far. Skillful doping of transition metal ions in nanostructures alter their spin degrees of freedom with promising giant Zeeman splitting 3,6 , magneto-optical 7 and fast spin-lattice dynamics 8. For instance, it activates a long range magnetic ordering crucial for spin-photonics 9 , spintronics 10 and carrier-induced magnetism 5. Moreover, the reports on doping manganese (Mn) ions are currently establishing the coexsistance of Mn 2+ /Mn 3+ states leading to various interactions and spin-allowed transitions 11. In particular to Mn doped bulk cadmium selenide ((Cd,Mn)Se), antiferromagnetism is stereotype 1,12,13 due to the short range d-d interactions. However, the calculations predict hole-induced long range ferromagnetism (FM) from nano-cluster state or co-doping 14,15. Besides this, M. Sawicki et al. 16 , G. L. Gutsev et al. 14,17,18 and J. Yang 19 expressed intriguing magnetic states and related spin-active optical properties depending upon the concentration and ionic coordinations of the dopant. Similarly, the optical studies of a very low Mn doped CdSe/ZnSe core-shell quantum dots 20,21 predicts insignificant role of an individual Mn 2+ on the properties of host lattice. Nevertheless, studies on different quantum structures report on quenchning and shifting 22 of optical properties with the Mn 2+ state. Despite of the low solubility, several groups have initiated the Mn doping in various structure and composition 23-25 regardless of the ordinary properties. However, the concerns over doping stabilization in multilayered nanostuctures and its correlated properties orginating from intra-layer and inter-layer connected electronic states are yet to be explored. In this work, we report on (i) the successful doping of Mn into the cadmium selenide (CdSe) multilayered nanosheets (LNSs) lattice using a solvothermal route, (ii) strain induced stabilization and co-exitance of Mn 2+ / Mn 3+ states leading to multi-phase magnetic ordering with sharp ferromagnetic ordering at temperature ~48 K,

Highly luminescent two dimensional excitons in atomically thin CdSe nanosheets