Gowri Manohari Arumugam

University of Valencia | UV · Instituto de Ciencia Molecular (ICMol)

All-inorganic lead halide perovskite nanocrystals have great potential in optoelectronics and photovoltaics. However, their biological applications have not been explored much owing to their poor stability and shallow penetration depth of ultraviolet (UV) excitation light into tissues. Interestingly, the combination of all-inorganic halide perovski...

Anion exchange is a convenient postsynthetic transformation method to adjust the composition and bandgap of semiconductors. However, it is still a challenge to achieve the desired halogen-variable perovskites due to rapid and uncontrollable reaction and difficulty to synthesize directly. Herein, a facile and gentle vapor/solid anion exchange strate...

Perovskite solar cells (PSCs) based on organometal halide (Omh) perovskites have been exhibited superb potential for next-generation photovoltaic applications because of their ever-increasing power conversion efficiencies over the past decade. However, their operational stability remains a challenge, which are attributed to the ionic nature of Omh...

Perovskite solar cells (PVSCs) are the most promising candidates in third-generation photovoltaic technologies with a certified efficiency of 25.2% within the past decades. They attract increasing attention owing to their ease of fabrication, cost-effectiveness, and lower processing temperature when compared to commercial silicon-based solar cells....

In the past decades, the inverted structure (p‐i‐n structure) perovskite solar cells (PVSCs) have been attracted more by the researchers owing to their ease of fabrication, cost‐effectiveness, lower processing temperature for the fabrication of large scale and flexible devices with negligible J−V hysteresis effects. The hole transporting layer (HTL...

The dynamically modulated lasing mode is extremely significant for laser applications in optical interconnections, on-chip communications and trace detection. However, tunable micro/nano laser (especially for single mode laser) is still a challenge although enormous efforts have been devoted. The coexisting modes could be selected out through light...

High concentration of LiNO 3 suppress hydrolysis of polyimide in alkaline solution. • The H + insert into carbonyl resulting in poor structural stability of polyimide. • LiOH colloids continuously releases OH − to control H + with relatively low level. • Polyimide in 0.001 M KOH@LiNO 3 electrolyte displays a long cyclability. In this work, the alka...

Lattice matching and passivation are generally seen as the main beneficial effects in 2D/3D perovskite heterostructured solar cells, but the understanding of the mechanisms involved is still incomplete. In this work, it is shown that 2D/3D heterostructure are unstable under common thermal processing conditions, caused by the lattice expansion of st...

All‐inorganic perovskite of CsPbBr3 thin films solar cells has attracted increasing interest in recent years due to its potential long‐term stability over the generally used hybrid perovskites. In this work, all‐inorganic CsPbBr3 perovskites are doped with Eu²⁺ to enhance the efficiency of perovskite solar cell. The perovskite films exhibit a bette...

Lithium‐sulfur (Li‐S) batteries with a high energy density and long lifespan are considered as promising candidates for next‐generation electrochemical energy‐storage devices. However, the sluggish redox kinetics of electrochemistry and high solubility of polysulfide during cycling render insufficient sulfur utilization and poor cycling stability....

Surface-enhanced Raman spectroscopy (SERS) has been successfully applied to detect various biomolecules, but it is still in challenge to assay living cells or bacteria sensitively, selectively and quantitatively in complex environments. In this paper, 4-ATP and DTNB are assembled on Ag nanoparticle (NP) -decorated poly (styrene-co-acrylic acid) (PS...

Designing a durable lithium metal anode for solid state batteries requires a controllable and uniform deposition of lithium, and the metal lithium layer should maintain a good interface contact with solid state electrolyte during cycles. In this work, we construct a robust functional interface layer on the modified Li-B electrode which considerably...

Although inorganic perovskite solar cells (PSCs) are promising in thermal stability, their large open‐circuit voltage (VOC) deficit and difficulty in large‐area preparation still limit their development toward commercialization. The present work tailors C60 via a codoping strategy to construct an efficient electron‐transporting layer (ETL), leading...

The development of bidirectional light emitting diodes (LEDs) is significant to avoid stroboscopic effects and save energy for illumination and display applications. However, the existing bidirectional LEDs present different electroluminescent (EL) emission spectra and intensity at forward and reverse bias conditions which causes stroboscopic effec...

Organic-inorganic perovskite solar cells (PSCs) have achieved an inspiring third-party-certificated power conversion efficiency (PCE) of 25.2%, which is comparable with commercialized silicon (Si) and copper indium gallium selenium solar cells. However, their notorious instability, including their deterioration at elevated temperature, is still a s...

Herein, we present a self-assembly strategy to prepare a cage-polymer coated sulfur sample.The sample embeds a graphene as a new sulfur cathode. The cathode exhibits an excellent electrochemical stability,which maintains...

Down-shifting and down-conversion processes are an effective way to improve the poor response of single crystalline silicon (c-Si) solar cells at shorter wavelength region. The Ce3+-doped YAG possesses a down-shifting (DS) process which converts ultra-violet (UV) and blue light into yellow light whereas Ce3+-Yb3+ co-doped YAG exhibits a down-convers...

In the past few decades, the fabrication of solar cells has been considered as one of the most promising ways to meet the increasing energy demands for the development of modern society as well as to control the environmental pollution which caused by fossil fuel combustion. The different types of solar cells such as silicon solar cells (Si), Cu-ba...

Metal nanoparticles assistant photoelectrochemical (PEC) biosensing has been attracted by point-of-care testing due to its fast and low background signal. But the interfacial charge transfer of plasmonic-enhanced biosensing is not fully understood still now. Herein, a plasmonic-enhanced PEC platform has been demonstrated for glutathione (GSH) detec...

The organic-inorganic hybrid halide perovskites are desirable candidates in the applications of photovoltaics as well as lasing. However, to enhance the lasing performances of these perovskites with lower threshold and higher quality factor is still a challenging issue. In this regards, the Fabry-Pérot resonator has been fabricated by using an acti...

A novelty bilinear suspension immunoassay biosensor is developed for Staphylococcus aureus specific detection. In the present study, a dual-color-based sandwich immunosensor was constructed for sensitive and selective detection of this bacterium. In this bioassay system, the monoclonal antibodies of Staphylococcus aureus were immobilized on carboxy...

Znic (Zn) surface plasmons (SPs) have been widely reported for its impressive performance in improving the optical properties of semiconductor nearby. Zn is an effective metal with SPs response in ultraviolet region, but the disadvantage of strong metal activity limits the application mentioned above. Here, in order to ensure the stability of metal...

Collaborative enhancements from surface plasmons (SPs) and whispering-gallery modes (WGMs) can induce intense near-field effects with high spatial localization around the surface of a semiconducting material. One can construct a highly efficient hybrid microcavity using semiconducting materials through resonant coupling between SPs and WGMs. Hexago...

Ever since the exploration of ZnO for ultraviolet (UV) lasers, realization of high performance lasing in hydrothermal samples is still a challenge due to the poor crytal quality. In this paper, high quality ZnO microcavities were fabricated by hydrothermal method with graphene as grown media. Structural, optical as well as the exciton dynamic prope...

Up-conversion nanostructures play a vital role in the application of bioimaging, but improving their red up-conversion emission is still a challenging issue. In this regard, an up-conversion system of RbPbI3:Er³⁺, Yb³⁺ nanowires with surface plasmons has been employed for improving the red up-conversion emission. It represents the dominant red emis...

Realization of pure and stable ultraviolet electroluminescence (UV EL) of ZnO light-emitting diode (LED) is still a challenging issue, due to complicated defects of intrinsic ZnO and the corresponding device interfaces. In this paper, we demonstrated a simple & feasible method to fabricate n-ZnO/AlN/p-GaN heterojunctions light-emitting devices. Fir...

It was observed the dramatic enhancement of the intrinsic spontaneous and stimulated emission as well as the ensuing suppression of the defect-related green emission in Au-decorated ZnO microrods. A series of spectral explore and theoretical discussion demonstrated an electron transfer assisted by surface plasmon (SP) resonant coupling between Au n...

An efficient near-infrared (NIR) down-conversion (DC) process has been demonstrated in Bi³⁺-Yb³⁺ co-doped Y3Al5O12 phosphors. The excitation spectra, emission spectra and decay curves were measured to prove the occurrence of energy transfer (ET) from Bi³⁺ → Yb³⁺. Upon the excitation of UV photons, NIR emission has been obtained at 1028 nm through t...

Zinc oxide/silver hollow spheres (ZnO/Ag HSs) have been synthesized and employed as both photocatalyst and antimicrobial agent. They possess an efficient photocatalysis to various organic molecular dyes such as methylene blue (MB), methyl orange (MO), phenol red (PhR) and rhodamine 6G (R6G). Among them, the MB reaches the degradation rate of 100% u...

Due to high absorption efficiency, long carrier diffusion length and low surface recombination velocity, micro and nano-lasers of lead halide perovskite have been extensively studied for the potential applications of optoelectronic devices and photonics integration. But, it is still in challenge to achieve a stable and controllable lasing action, e...

Single-doped (Ce³⁺,Tb³⁺), co-doped (Ce³⁺-Tb³⁺, Ce³⁺-Yb³⁺, Tb³⁺-Yb³⁺) and tri-doped (Ce³⁺-Tb³⁺-Yb³⁺) Y3Al5O12 phosphors were synthesized by a solid-state reaction method. The XRD, excitation and emission spectra and the fluorescence lifetime of the samples were measured. The energy transfer mechanism was also investigated. The results showed that th...

ZnO microrods are synthesized using the vapor phase transport method, and the magnetron sputtering is used to decorate the Al nanoparticles (NPs) on a single ZnO microrod. The micro-PL and I–V responses are measured before and after the decoration of Al NPs. The FDTD stimulation is also carried out to demonstrate the optical field distribution arou...

The porous structured zinc oxide (ZnO) microspheres decorated with silver nanoparticles (Ag NPs) have been fabricated as surface-enhanced Raman scattering (SERS) substrate for ultra-sensitive, highly reproducible and stable biological/chemical sensing of various organic molecules. The ZnO microspheres were hydrothermally synthesized without any tem...

Bromine-based methylammonium lead hybrid perovskite (CH3NH3PbBr3 or MAPbBr3) has been exhibited remarkable charge transport and optical properties. Nonetheless, the photoluminescence (PL) behavior and electronic transition state are still obscure. In this paper, the intrinsic emission mechanisms of two peaked CH3NH3PbBr3 microcuboid crystals have b...

Ce³⁺–Yb³⁺ co-doped Y3Al5O12 phosphors are one of most the potential candidates of down-conversion materials for photovoltaic cells. To improve the near-infrared emission from Yb³⁺ ions, Bi³⁺ ions were introduced into the phosphors. The experimental results showed that the intensity of Yb³⁺ emission was greatly enhanced after doping Bi³⁺ ions into t...

Graphene quantum dots (GQDs) offer new opportunities for the applications of electrochemical sensing because of their intrinsic peroxidase-like activity. To develop a sensitive electrochemical sensor with better stability and reproducibility, polydopamine (PDA) has been employed as an adhesive agent to integrate the GQDs and gold nanoparticles (Au...

In this work, perovskite CH3NH3PbI3 (MAPbI3) microwires has been synthesized via a simple solution self-assembly method for facile fabrication of photoelectronic devices. A two-step growth process was proposed to elucidate the formation and growth mechanisms of the microwires. Also, a photodetector was fabricated and analyzed its photoresponse char...

Dopamine (DA) is a potential neuro modulator in the brain which influences a variety of motivated behaviors and plays a key role in life science. A hybrid ZnO/Ag microcavity based on Whispering Gallery Mode (WGM) effect has been developed for ultrasensitive detection of dopamine. Utilizing this effect of structural cavity mode, a Raman signal of R6...

Copper doped tin sulphide (SnS: Cu) thin films have been prepared by the spray pyrolysis technique at the substrate temperature of 350 �C. The optical and electrical properties of the films were studied as a function of copper dopant concentration (up to 10 at.%). The optical measurements showed the energy band gap, refractive index and extinction co...

Antimony doped tin disulphide (SnS2:Sb) thin films have been prepared by the spray pyrolysis technique at the substrate temperature of 300 1C. The properties of the films were studied as a function of antimony dopant concentration (up to 10 at%). The XRD analysis revealed that the films were polycrystalline in nature and having hexagonal crystal struc...

A spray pyrolysis technique was used to deposit the silver doped tin sulfide (SnS:Ag) thin films on glass substrates at the substrate temperature of 350 degrees C. The variation in structural, optical and electrical properties of SnS with silver incorporation was investigated. The XRD spectra showed the improvement in crystallinity while increasing...

Bismuth doped tin sulfide (SnS:Bi) thin films were deposited onto glass substrates by the spray pyrolysis technique at the substrate temperature of 350 °C. The effect of doping concentration [Bi/Sn] on their structural, optical and electrical properties was investigated as a function of bismuth doping between 0 and 8 at%. The XRD results showed tha...

tTin sulphide (SnS) thin films were deposited on glass substrate at different substrate temperature(Ts= 325◦C, 350◦C and 375◦C) by pyrolytic decomposition using stannous chloride and thiourea as pre-cursor solutions. Also, indium-doped SnS thin films were prepared by using InCl3as dopant source. Thedopant concentration [In/Sn] was varied from 2 at%...

Titanium dioxide (TiO2) thin films have been deposited on microscopic glass substrate by spray pyrolysis technique. The effect of deposition parameters such as substrate temperature, molarity (precursor concentration) and solution spray rate on the structural, surface morphological and optical properties of the films have been studied. The prepared...

Tin sulphide (SnS) thin films were deposited on microscopic glass substrate at different substrate temperatures by pyrolytic decomposition using stannous chloride and thiourea as precursor solution. The physical properties of the films were studied using XRD, UV and Hall Effect measurements. The films formed for temperature of 350 C was single p...

Transparent thin films of CdO has been deposited on to glass substrates employing chemical bath deposition. The prepared films are reproducible, adherent to the substrate, pinhole free and uniform. Amongst the different process parameters, the deposition time plays a significant role in obtaining device quality transparent CdO thin films. X-ray pow...