This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosen... more This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosensitizer in the fabrication of self-powered photosensors via dye-sensitized solar cells (DSSCs). Various photoanodes, including ZnO, ZnO/TiO 2 , and ZnO/TiO 2 /Nb 2 O 5 , were investigated for their performance enhancement in DR-based photosensors. The photoanodes were fabricated using different deposition methods sensitized with DR photosensitizer and characterized through X-ray diffraction analysis, Field emission scanning electron microscopy (FE-SEM), UV-visible, Fluorescence spectroscopy, and Fourier transform infrared spectroscopy (FTIR) analysis. The absorbance spectrum results indicate improved photosensitizer adsorption in visible light for the ZnO/TiO 2 / Nb 2 O 5 /DR photoanode compared to other configurations. The scanning electron microscopy (SEM) cross-section image of ZnO/TiO 2 /Nb 2 O 5 confirmed the formation of a multilayer photoanode. Chronoamperometry experiments were conducted to evaluate the photo sensing behavior, focusing on sensitivity, photoresponsivity, specific detectivity, and quantum efficiency within the solar spectrum range. Among the devices, ZnO/TiO 2 /Nb 2 O 5 exhibited the highest photoresponsivity (1.2 × 10 −3 A/W) and photodetectivity (26.78 × 10 4 Jones), demonstrating promising advancements in DR-sensitized photosensors. This research highlights the exceptional performance of DR-sensitized photoanodes, particularly ZnO/TiO 2 /Nb 2 O 5 , in advancing the capabilities of photo-sensing devices. The investigated configuration exhibited a rapid response speed of 723 ms and a remarkable sensitivity of 89.87% in detecting photo signals. These findings emphasize the potential of DR photosensitizers to enhance photo-sensing activities, with significant implications for diverse applications in photodetection. By leveraging the unique properties of DR, particularly its incorporation into ZnO/TiO 2 /Nb 2 O 5 , this study underscores the promising prospects for developing efficient self-powered photosensors. The insights gleaned from this work pave the way for further exploration and optimization in organic photosensors.
This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosen... more This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosensitizer in the fabrication of self-powered photosensors via dye-sensitized solar cells (DSSCs). Various photoanodes, including ZnO, ZnO/TiO 2 , and ZnO/TiO 2 /Nb 2 O 5 , were investigated for their performance enhancement in DR-based photosensors. The photoanodes were fabricated using different deposition methods sensitized with DR photosensitizer and characterized through X-ray diffraction analysis, Field emission scanning electron microscopy (FE-SEM), UV-visible, Fluorescence spectroscopy, and Fourier transform infrared spectroscopy (FTIR) analysis. The absorbance spectrum results indicate improved photosensitizer adsorption in visible light for the ZnO/TiO 2 / Nb 2 O 5 /DR photoanode compared to other configurations. The scanning electron microscopy (SEM) cross-section image of ZnO/TiO 2 /Nb 2 O 5 confirmed the formation of a multilayer photoanode. Chronoamperometry experiments were conducted to evaluate the photo sensing behavior, focusing on sensitivity, photoresponsivity, specific detectivity, and quantum efficiency within the solar spectrum range. Among the devices, ZnO/TiO 2 /Nb 2 O 5 exhibited the highest photoresponsivity (1.2 × 10 −3 A/W) and photodetectivity (26.78 × 10 4 Jones), demonstrating promising advancements in DR-sensitized photosensors. This research highlights the exceptional performance of DR-sensitized photoanodes, particularly ZnO/TiO 2 /Nb 2 O 5 , in advancing the capabilities of photo-sensing devices. The investigated configuration exhibited a rapid response speed of 723 ms and a remarkable sensitivity of 89.87% in detecting photo signals. These findings emphasize the potential of DR photosensitizers to enhance photo-sensing activities, with significant implications for diverse applications in photodetection. By leveraging the unique properties of DR, particularly its incorporation into ZnO/TiO 2 /Nb 2 O 5 , this study underscores the promising prospects for developing efficient self-powered photosensors. The insights gleaned from this work pave the way for further exploration and optimization in organic photosensors.
This research focuses on the first demonstration of NO2Lw (2-hydroxy-3-nitronaphthalene-1,4-dione... more This research focuses on the first demonstration of NO2Lw (2-hydroxy-3-nitronaphthalene-1,4-dione) as a photosensitizer and TiO2, ZnO, and Nb2O5 as photoanode materials for dye-sensitized solar cells (DSSCs). The metal-free organic photosensitizer (i.e., nitro-group-substituted naphthoquinone, NO2Lw) was synthesized for this purpose. As a photoanode material, metal oxides, such as TiO2, ZnO, and Nb2O5, were selected. The synthesized NO2Lw contains an electron-withdrawing group (−NO2) and anchoring groups (−OH) that exhibit absorption in the visible range. The UV–visible absorbance spectrum of NO2Lw demonstrates the absorption ascribed to ultraviolet and visible region charge transfer. The NO2Lw interacts with the TiO2, ZnO, and Nb2O5 photoanode, as shown by bathochromic shifts in wavelengths in the photosensitizer-loaded TiO2, ZnO, and Nb2O5 photoanodes. FT-IR analysis also studied the bonding interaction between NO2Lw and TiO2, ZnO, and Nb2O5 photoanode material. The TiO2, ZnO, and Nb2O5 photoanodes loaded with NO2Lw exhibit a shift in the wavenumber of the functional groups, indicating that these groups were involved in loading the NO2Lw photosensitizer. The amount of photosensitizer loading was calculated, showing that TiO2 has higher loading than ZnO and Nb2O5 photoanodes; this factor may constitute an increased JSC value of the TiO2 photoanode. The device performance is compared using photocurrent–voltage (J–V) curves; electrochemical impedance spectroscopy (EIS) measurement examines the device’s charge transport. The TiO2 photoanode showed higher performance than the ZnO and Nb2O5 photoanodes in terms of photoelectrochemical properties. When compared to ZnO and Nb2O5 photoanodes-based DSSCs, the TiO2 photoanode Bode plot shows a signature frequency peak corresponding to electron recombination rate toward the low-frequency region, showing that TiO2 has a greater electron lifetime than ZnO and Nb2O5 photoanodes based DSSCs.
Niobium pentoxide (Nb2O5) blocking layers are a considerable and effective photoanode material in... more Niobium pentoxide (Nb2O5) blocking layers are a considerable and effective photoanode material in the fabrication of highly efficient dye-sensitized solar cells (DSSCs) due to their higher conduction band edge position than that of titania (TiO2) and zinc oxide (ZnO). Therefore, higher open-circuit voltage and more significant electron lifetime can be achieved along with chemical stability, and improved conversion efficiencies. In the present review, the application of Nb2O5 in the fabrication of DSSCs is discussed with detailed examples. The challenges and potential approaches are discussed as well.
The present work deals with the study of Nb2O5 photoanode with low cost rose Bengal dye for dye s... more The present work deals with the study of Nb2O5 photoanode with low cost rose Bengal dye for dye sensitized solar cell (DSSC) application. Chemical route was used for preparation of nano-crystalline niobium pentaoxide (Nb2O5) and doctor blade method was employed for deposition of Nb2O5 films. The morphological and structural analysis of Nb2O5 photoanodes were carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. The SEM micrograph shows spherical granular grains with porous structure useful for dye adsorption. The XRD analysis shows the formation of pure orthorhombic phase of Nb2O5. The band gap value for Nb2O5 photoanode was calculated as 3.2 eV using diffused reflectance spectroscopy (DRS). As an alternative to conventional ruthenium dye, we used rose Bengal (4, 5, 6, 7-tetrachloro- 20, 40, 50, 70 tetra-iodo-fluorescein) dye, which acts as a photo-sensitizer for DSSCs. The absorbance spectra of the rose Bengal dye was investigated by UV-visible spectrophotometer. The...
A simple soft chemical approach has been successfully adopted for the synthesis of ZnO aggregates... more A simple soft chemical approach has been successfully adopted for the synthesis of ZnO aggregates which are having the average diameters of about 400 nm were prepared at 80 °C by polyol process from zinc acetate (Zinc source), polyvinyl pyrrolidone (PVP; capping agent) and ethylene glycol (EG; solvent). The films are comprised of polydispersed ZnO aggregates having crystallite size around 15 nm. The morphologies of as-prepared ZnO samples were characterized by using Scanning Electron Microscopy where the diameters of ZnO aggregates ranging from several tens to several hundreds of nanometers and the X-ray diffraction patterns confirm the hexagonal crystal structure of the ZnO. In the present work this sample is selected for fabricating Dye Sensitized Solar Cells (DSSC) and their photovoltaic properties were measured. DSSC's are photo-electrochemical solar cells and the ZnO electrode was dye sensitize by using organic textile dye Reactive Blue 59.
This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosen... more This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosensitizer in the fabrication of self-powered photosensors via dye-sensitized solar cells (DSSCs). Various photoanodes, including ZnO, ZnO/TiO 2 , and ZnO/TiO 2 /Nb 2 O 5 , were investigated for their performance enhancement in DR-based photosensors. The photoanodes were fabricated using different deposition methods sensitized with DR photosensitizer and characterized through X-ray diffraction analysis, Field emission scanning electron microscopy (FE-SEM), UV-visible, Fluorescence spectroscopy, and Fourier transform infrared spectroscopy (FTIR) analysis. The absorbance spectrum results indicate improved photosensitizer adsorption in visible light for the ZnO/TiO 2 / Nb 2 O 5 /DR photoanode compared to other configurations. The scanning electron microscopy (SEM) cross-section image of ZnO/TiO 2 /Nb 2 O 5 confirmed the formation of a multilayer photoanode. Chronoamperometry experiments were conducted to evaluate the photo sensing behavior, focusing on sensitivity, photoresponsivity, specific detectivity, and quantum efficiency within the solar spectrum range. Among the devices, ZnO/TiO 2 /Nb 2 O 5 exhibited the highest photoresponsivity (1.2 × 10 −3 A/W) and photodetectivity (26.78 × 10 4 Jones), demonstrating promising advancements in DR-sensitized photosensors. This research highlights the exceptional performance of DR-sensitized photoanodes, particularly ZnO/TiO 2 /Nb 2 O 5 , in advancing the capabilities of photo-sensing devices. The investigated configuration exhibited a rapid response speed of 723 ms and a remarkable sensitivity of 89.87% in detecting photo signals. These findings emphasize the potential of DR photosensitizers to enhance photo-sensing activities, with significant implications for diverse applications in photodetection. By leveraging the unique properties of DR, particularly its incorporation into ZnO/TiO 2 /Nb 2 O 5 , this study underscores the promising prospects for developing efficient self-powered photosensors. The insights gleaned from this work pave the way for further exploration and optimization in organic photosensors.
This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosen... more This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosensitizer in the fabrication of self-powered photosensors via dye-sensitized solar cells (DSSCs). Various photoanodes, including ZnO, ZnO/TiO 2 , and ZnO/TiO 2 /Nb 2 O 5 , were investigated for their performance enhancement in DR-based photosensors. The photoanodes were fabricated using different deposition methods sensitized with DR photosensitizer and characterized through X-ray diffraction analysis, Field emission scanning electron microscopy (FE-SEM), UV-visible, Fluorescence spectroscopy, and Fourier transform infrared spectroscopy (FTIR) analysis. The absorbance spectrum results indicate improved photosensitizer adsorption in visible light for the ZnO/TiO 2 / Nb 2 O 5 /DR photoanode compared to other configurations. The scanning electron microscopy (SEM) cross-section image of ZnO/TiO 2 /Nb 2 O 5 confirmed the formation of a multilayer photoanode. Chronoamperometry experiments were conducted to evaluate the photo sensing behavior, focusing on sensitivity, photoresponsivity, specific detectivity, and quantum efficiency within the solar spectrum range. Among the devices, ZnO/TiO 2 /Nb 2 O 5 exhibited the highest photoresponsivity (1.2 × 10 −3 A/W) and photodetectivity (26.78 × 10 4 Jones), demonstrating promising advancements in DR-sensitized photosensors. This research highlights the exceptional performance of DR-sensitized photoanodes, particularly ZnO/TiO 2 /Nb 2 O 5 , in advancing the capabilities of photo-sensing devices. The investigated configuration exhibited a rapid response speed of 723 ms and a remarkable sensitivity of 89.87% in detecting photo signals. These findings emphasize the potential of DR photosensitizers to enhance photo-sensing activities, with significant implications for diverse applications in photodetection. By leveraging the unique properties of DR, particularly its incorporation into ZnO/TiO 2 /Nb 2 O 5 , this study underscores the promising prospects for developing efficient self-powered photosensors. The insights gleaned from this work pave the way for further exploration and optimization in organic photosensors.
This research focuses on the first demonstration of NO2Lw (2-hydroxy-3-nitronaphthalene-1,4-dione... more This research focuses on the first demonstration of NO2Lw (2-hydroxy-3-nitronaphthalene-1,4-dione) as a photosensitizer and TiO2, ZnO, and Nb2O5 as photoanode materials for dye-sensitized solar cells (DSSCs). The metal-free organic photosensitizer (i.e., nitro-group-substituted naphthoquinone, NO2Lw) was synthesized for this purpose. As a photoanode material, metal oxides, such as TiO2, ZnO, and Nb2O5, were selected. The synthesized NO2Lw contains an electron-withdrawing group (−NO2) and anchoring groups (−OH) that exhibit absorption in the visible range. The UV–visible absorbance spectrum of NO2Lw demonstrates the absorption ascribed to ultraviolet and visible region charge transfer. The NO2Lw interacts with the TiO2, ZnO, and Nb2O5 photoanode, as shown by bathochromic shifts in wavelengths in the photosensitizer-loaded TiO2, ZnO, and Nb2O5 photoanodes. FT-IR analysis also studied the bonding interaction between NO2Lw and TiO2, ZnO, and Nb2O5 photoanode material. The TiO2, ZnO, and Nb2O5 photoanodes loaded with NO2Lw exhibit a shift in the wavenumber of the functional groups, indicating that these groups were involved in loading the NO2Lw photosensitizer. The amount of photosensitizer loading was calculated, showing that TiO2 has higher loading than ZnO and Nb2O5 photoanodes; this factor may constitute an increased JSC value of the TiO2 photoanode. The device performance is compared using photocurrent–voltage (J–V) curves; electrochemical impedance spectroscopy (EIS) measurement examines the device’s charge transport. The TiO2 photoanode showed higher performance than the ZnO and Nb2O5 photoanodes in terms of photoelectrochemical properties. When compared to ZnO and Nb2O5 photoanodes-based DSSCs, the TiO2 photoanode Bode plot shows a signature frequency peak corresponding to electron recombination rate toward the low-frequency region, showing that TiO2 has a greater electron lifetime than ZnO and Nb2O5 photoanodes based DSSCs.
Niobium pentoxide (Nb2O5) blocking layers are a considerable and effective photoanode material in... more Niobium pentoxide (Nb2O5) blocking layers are a considerable and effective photoanode material in the fabrication of highly efficient dye-sensitized solar cells (DSSCs) due to their higher conduction band edge position than that of titania (TiO2) and zinc oxide (ZnO). Therefore, higher open-circuit voltage and more significant electron lifetime can be achieved along with chemical stability, and improved conversion efficiencies. In the present review, the application of Nb2O5 in the fabrication of DSSCs is discussed with detailed examples. The challenges and potential approaches are discussed as well.
The present work deals with the study of Nb2O5 photoanode with low cost rose Bengal dye for dye s... more The present work deals with the study of Nb2O5 photoanode with low cost rose Bengal dye for dye sensitized solar cell (DSSC) application. Chemical route was used for preparation of nano-crystalline niobium pentaoxide (Nb2O5) and doctor blade method was employed for deposition of Nb2O5 films. The morphological and structural analysis of Nb2O5 photoanodes were carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. The SEM micrograph shows spherical granular grains with porous structure useful for dye adsorption. The XRD analysis shows the formation of pure orthorhombic phase of Nb2O5. The band gap value for Nb2O5 photoanode was calculated as 3.2 eV using diffused reflectance spectroscopy (DRS). As an alternative to conventional ruthenium dye, we used rose Bengal (4, 5, 6, 7-tetrachloro- 20, 40, 50, 70 tetra-iodo-fluorescein) dye, which acts as a photo-sensitizer for DSSCs. The absorbance spectra of the rose Bengal dye was investigated by UV-visible spectrophotometer. The...
A simple soft chemical approach has been successfully adopted for the synthesis of ZnO aggregates... more A simple soft chemical approach has been successfully adopted for the synthesis of ZnO aggregates which are having the average diameters of about 400 nm were prepared at 80 °C by polyol process from zinc acetate (Zinc source), polyvinyl pyrrolidone (PVP; capping agent) and ethylene glycol (EG; solvent). The films are comprised of polydispersed ZnO aggregates having crystallite size around 15 nm. The morphologies of as-prepared ZnO samples were characterized by using Scanning Electron Microscopy where the diameters of ZnO aggregates ranging from several tens to several hundreds of nanometers and the X-ray diffraction patterns confirm the hexagonal crystal structure of the ZnO. In the present work this sample is selected for fabricating Dye Sensitized Solar Cells (DSSC) and their photovoltaic properties were measured. DSSC's are photo-electrochemical solar cells and the ZnO electrode was dye sensitize by using organic textile dye Reactive Blue 59.
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Papers by Niyamat I . Beedri