Positive Photoconducting Nature Research Articles

Nucleation, crystal growth, XRD, optical, electrical, PC, SEM, SHG and Z-scan analysis of LHPP for NLO and optical limiting application

High-quality organic L-histidinium 4-nitrophenolate 4-nitrophenol (LHPP) single crystals were grown using an aqueous solution. The crystals were grown using slow evaporation solution technique (SEST) at a temperature of 40°C using a constant temperature bath (CTB). Nucleation growth rates were monitored for various durations using an optical microscope. The crystalline perfection was confirmed through sharp, high-intensity diffraction peaks observed in the theoretical and experimental powder X-ray diffraction (PXRD) analysis, which also confirmed the monoclinic crystal structure with the noncentrosymmetric P21 space group. The crystallite size and strain were calculated using Williamson–Hall coefficient. Vibrational frequency assignments of LHPP were determined using FTIR spectroscopic analysis. Optical properties were studied using UV–Vis NIR spectroscopic studies, which showed that the crystals have very low absorption and high transmittance in the entire visible region. Additionally, the optical energy bandgap (Eg) was calculated and found to be 6.15[Formula: see text]eV. Luminescence properties were studied using fluorescence (FL) analysis. Dielectric investigations were subjected to varying frequencies to study the suitability of the crystal for transistor application. The positive photoconductive (PC) nature of the crystal was confirmed using photoconductivity studies to confirm suitability for photodetector devices that measure the intensity of light rays. Etching studies revealed the growth pattern and the formation of different kinds of etch pits. The surface morphology was studied using scanning electron microscopy (SEM) and electrochemical studies were also carried out. The relative second harmonic generation (SHG) efficiency of the material was also examined and found to be 1.34 times that of standard KDP. The optical limiting and higher-order nonlinear optical (NLO) properties of the grown crystals were studied by the [Formula: see text]-scan method using a Nd: YAG laser functioning at 532[Formula: see text]nm.

Nucleation kinetics, chemical etching, hirshfeld surface, and photoluminescence of Rubidium hydrogen oxalate dihydrate NLO single crystal

The nucleation dynamics of a semi-organic Rubidium hydrogen oxalate dihydrate (RbHOH) crystal were assessed using double-distilled water as a solvent medium to obtain good quality crystal using the solution growth technique. Gravimetric analysis of solubility revealed that it has a positive temperature coefficient of solubility, which is appropriate for bulk growth. Other nucleation parameters such as metastable zonewidth, induction period, and interfacial energy were carried out using the classical theory of nucleation. The photoconductivity experiments reveal that the grown crystal exhibits a positive photoconductivity nature. Chemical etching and atomic force microscopy (AFM) experiments were performed on the produced crystal surface. From AFM experiments, effectively assessed amplitude parameters were calculated. Etching studies showed the presence of etch pit patterns such as tiny hillocks and rectangular shapes. Intermolecular interactions were analysed by using Hirshfeld surface analysis. In the photoluminescence (PL) studies, the grown crystal indicates green emission peaks at 519 nm, and the bandgap energy is found to be 4.8 eV. At room temperature, the refractive index of the RbHOH crystal was determined to be 1.669. The nonlinear optical (NLO) efficiency of the grown crystal was examined using a second harmonic generation efficiency test, and it was determined to be 0.58 times that of KDP.

Synthesis, crystal growth and characterization of piperazinium 5-nitrosalicylate (P5NS) single crystal for nonlinear optical (NLO) applications

A single crystal of Piperazinium 5-nitrosalicylate (P5NS) was grown by using slow evaporation solution technique (SEST). The structural analysis (crystal system & cell parameter) of the grown P5NS crystal was examined by single crystal XRD and it exposed that the P5NS crystal has a crystal triclinic system and space group (P-1). Using powder XRD analysis, miller index and (h k l) planes were identified. The P5NS crystal has a sharp cutoff wavelength around 380 nm and is transparent in UV region. The FTIR analysis was investigated on the P5NS crystal to find out the P5NS functional groups. The thermogravimetric and differential thermal analysis illustrate that the P5NS crystal is thermally stable upto 255 °C. Further increase in the temperature resulted in decomposition of P5NS. The etch pit density of P5NS crystal has been calculated by using the chemical etching analysis. The Photoconductivity study reveals that the grown PMC crystal has positive photoconductive nature. The electrical properties, dielectric constant and dielectric loss were determined. The laser damage threshold (LDT) analysis was investigated by Nd: YAG laser and the wavelength of laser is 1064 nm. Intermolecular interactions of P5NS is executed by the Hirshfeld surface analysis. The NLO susceptibility (χ(3)) was calculated by the Z-scan method using the source of He-Ne laser, whose wavelength is 632.8 nm.

Growth, SHG, Z-scan, optical limiting and quantum chemical investigation of hexamethylenetetraminium hydrogen DL-malate – An organic crystal for optoelectronic applications

Single crystals of hexamethylenetetraminium hydrogen dl-malate (HMTM) have been successfully synthesized by slow evaporation method and structurally analyzed by single crystal X-ray diffraction, powder X-ray diffraction, FTIR, FT-Raman, 1H and 13C NMR spectroscopic techniques. These investigations confirm the formation of HMTM crystal which crystallize in the non-centrosymmetric space group Cc with monoclinic crystal system. The N–H⋯O and O–H⋯O intermolecular hydrogen bonding interactions have been investigated by Hirshfeld surface analysis. The optical absorption cut-off wavelength of the grown crystal is observed at 353 nm in the UV–visible spectrum. From the photoluminescence spectrum, two intense emission peaks are identified at 312 nm and 415 nm. Dielectric study reveals low values of dielectric constant and dielectric loss. The positive photoconducting nature of HMTM is identified from the photoconductivity analysis. Second harmonic generation efficiency of the powdered HMTM is found to be 1.25 times greater than that of powdered KDP. The Z-scan and optical limiting results indicate that HMTM exhibits self-defocusing nature and optical limiting response, respectively. In addition, charge transfer interactions, first- and second-order hyperpolarizability values are computed by density functional theory calculations and are discussed in detail.

Studies on the growth aspects of L-alanine and lithium sulfate doped L-alanine single crystals for electro-optic applications

Single crystals of L-alanine and Lithium sulfate doped L-alanine crystals were successfully grown by the slow evaporation method. The powder XRD studies were used to analyze the crystalline nature of the crystals. ICP analysis confirms the presence of lithium in the grown L-alanine crystal. The optical bandgap of grown crystals was measured by UV–Vis spectroscopy, and different functional groups present in the grown crystals have been identified by the FTIR spectral analysis. The dielectric studies of the grown crystals were performed at different temperatures as a function of the frequency. The photoconductivity study contributed its positive photoconducting nature. The second harmonic generation for the grown crystal was confirmed by the Kurtz–Perry technique.

Growth and characterization of L-tyrosine magnesium chloride single crystal: A promising NLO crystal

New single Crystal of L-Tyrosine Magnesium Chloride (LTMC) was grown from aqueous solution by slow evaporation solution technique (SEST). The grown crystal was subjected to single crystal X-ray diffraction study which confirms that the grown crystal is orthorhombic system with the space group Pmn21. The grown crystals were characterized by Fourier Transform Infrared (FTIR) spectroscopic analysis to find the different modes of vibration due to various functional groups present in LTMC. The transmission spectrum of LTMC was recorded by UV–Vis spectrometer in the range between 200 nm and 800 nm which addressed the grown crystal has good optical transparency in the entire visible region and its energy band gap was determined. The thermal stability of the crystal was determined from thermo gravimetric and differential thermo analysis (TG-DTA) curve. The dielectric constant and dielectric loss has been studied as a function of frequency for various temperatures and the results were discussed in details. The frequency dependence of AC/DC conductivity studies for different temperature was carried out. The photoconductive behavior of the material is also investigated and the grown crystal has positive photoconductive nature. Mechanical strength of the grown crystal was estimated by using Vicker’s hardness test. The presence of second harmonic generation (SHG) for the grown crystal was confirmed by Kurtz Perry powder technique. All these studies indicate that the LTMC crystal can be considered as a potential candidate for the fabrication of optoelectronic devices.

Spectroscopic and density functional theory (DFT) approach of zwitterionic 4-aminobenzenesulfonic acid for optoelectronic applications

In this present study, a coupled experimental and density functional theory (DFT) studies of organic nonlinear optical (NLO) material, 4-aminobenzenesulfonic acid (4AB), is reported. By slow evaporation method the optical quality, single crystals of 4AB were developed under aqueous medium condition. Single-crystal XRD analysis reveals the crystalline nature of 4AB crystal; the 4AB crystal structure is in the orthorhombic system with noncentrosymmetric (NCS), Pca21, space group. The morphology of developed crystal has been indexed and showed a major facet of the crystal as (002). The molecular construction of 4AB has been well established using 13C and 1H NMR spectroscopic studies. FTIR and FT-RAMAN were found out to be the corresponding vibrational modes of 4AB. Linear optical studies of grown crystal allow near-UV cut-off wavelength range at 261 nm with good optical transparency in the visible and near-IR region and exhibited ultraviolet wavelength emission. Thermal analysis revealed a high thermal stability value of 288 °C for 4AB crystal. Moreover, dielectric and photoconductivity investigations were accomplished efficiently and revealed low dielectric constant and positive photoconducting nature, respectively. The molecular structure of 4AB was optimized at the B3LYP/cc-pVTZ basis set using density functional theory (DFT). The intermolecular hydrogen bond (N1–H1···O1) formation was confirmed by the Mulliken atomic charge distribution analysis and molecular electrostatic potential map analysis. Frontier molecular orbitals (FMOs) evidenced the lower energy gap for the 4AB molecule. Besides NLO properties, the dipole moment (µ0), polarizability (α) and first-order hyperpolarizability (β) were measured for the optimized 4AB molecule.

Growth and characterization of organic scintillation single crystal 1,1,4,4-Tetraphenyl-1,3-Butadiene (TPB) using vertical Bridgman technique

Abstract Studies on organic scintillation single crystal 1,1,4,4-Tetraphenyl-1,3-Butadiene (TPB) grown by vertical Bridgman technique for the first time is reported. Structural analysis was carried out with Single crystal and Powder X-ray diffractometer which is confirmed the cell parameters of the grown crystal. A definite vibrational analysis was identified on the fundamental modes of vibration. The refractive index of 1.618 was recorded by Abbe refractometer. UV–Vis near IR spectrum was used to determine the absorption edge and found to be 419 nm. The bandgap energy of the crystal was found to be 2.89 eV. Fluorescence spectra of the crystal exhibit a broad emission band at 440 nm. The fluorescence lifetime of TPB measured by TCSPC method reveals a short decay time of 16 ns for prompt and 40 ns for delayed. Photoconductivity of TPB exhibits the positive photoconductivity nature. The Vickers microhardness were used to determine the hardness number (Hυ) and Meyers index of the grown crystal. Essential Mechanical properties such as stiffness constant and yield strength were calculated. Chemical etching was carried out to study the defects and growth mechanism involved in the grown crystal and the etching characteristics of the crystal surface enunciate the 2-dimensional layer growth.

Investigation on synthesis, laser damage threshold, and NLO properties of l-asparagine thioacetamide single crystal for photonic device applications

The optically colorless l-asparagine thioacetamide (LATA) single crystal was grown by the slow evaporation method at room temperature with water as a solvent. The lattice parameters of the grown crystal have been analyzed by the single crystal X-ray diffraction and it belongs to orthorhombic system with space group P212121. The crystalline nature of the title material was confirmed by powder XRD analysis. The functional groups were confirmed by using FT-IR spectral analysis. The grown crystal has a UV cut-off wavelength at 236 nm and various optical parameters were analyzed theoretically by using UV–Visible transmittance data. The enhancement of second harmonic generation efficiency of LATA crystal was found to be 2.4 times higher than that of standard KDP. The laser damage threshold of LATA crystal is determined as 13.47 J/cm2 by using Nd–YAG laser operated at 1064 nm. In the photoluminescence spectrum, the sharp emission peak was noticed at 470 nm which implies the blue emission. The grown crystal shows the positive photoconductive nature. The fluctuation of dielectric permittivity (Ɛo) and dielectric loss (tan δ) were analyzed at different temperatures as a function of frequency. The grown crystal was thermally stable up to 110.38 °C and it was assessed by (TG/DTA) analysis. The Vickers microhardness test was accomplished to identify the mechanical stability of the grown crystal. Hence, LATA crystal is the most suitable material for the optoelectronic device applications.

Growth, spectroscopic, electrical and mechanical studies on hexamethylenetetramine succinate crystal: a new third harmonic generation material

Abstract Hexamethylenetetramine succinate was synthesized and good quality single crystals with the size of 14 mm × 6 mm × 4 mm were grown by the slow evaporation solution growth technique at room temperature. The single crystal XRD revealed that the grown crystal belongs to the monoclinic system with the space group of P21/c. The presence of functional groups in the crystal was identified using FT-IR technique. The optical behavior was examined through UV-Vis-NIR studies. The photoconductivity study exhibited the positive photoconductivity nature of the grown crystal. Microhardness studies revealed the soft nature of the crystal. The nonlinear refractive index (n2), nonlinear absorption coefficient (β) and third order nonlinear optical susceptibility χ(3) of the crystals were measured by Z-scan studies.

Biofriendly and competent domestic microwave assisted method for the synthesis of ZnO nanoparticles from the extract of Azadirachta indica leaves

ZnO nanoparticles are successfully prepared via eco-friendly synthesis using Azadirachta indica leaves extract with microwave assisted solvothermal method using a domestic microwave oven. The structure of green synthesized ZnO NPs and lattice parameters were confirmed using powder X-ray diffraction. Scanning electron microscopy and energy dispersive X-ray analysis exhibit the morphology and elemental analysis of the green synthesized ZnO NPs. The photoconductivity study reveals the positive photoconductive nature of ZnO nanoparticles.

Importance of cesium carbonate additives in the nucleation and growth of α- and γ-glycine single crystals

In the present work, successful growth of α- and γ-glycine single crystals using cesium carbonate (Cs2CO3) as an additive has been reported. The powder XRD study confirms that the grown 0.2 M cesium carbonate added glycine crystal has α-glycine crystal morphology and it crystallized in a monoclinic crystal structure with a space group of P21/n. In a similar manner, the PXRD patterns recorded for 0.4, 0.6, 0.8 and 1 M concentrations of cesium carbonate added glycine crystals and the obtained PXRD patterns authenticated that the harvested grown crystals belong to hexagonal crystal system with space group P31. The variation of dielectric constant and dielectric loss for the γ-glycine single crystal was carried out as a function of frequency and the results were discussed in detail. The transmittance spectrum shows that the grown α- and γ-glycine crystals had an extensive optical transparency window in the entire spectrum especially in visible region. The band gap varies from 4.59 to 6.01eV. The positive photoconducting nature of the grown γ-glycine single crystal in the presence of cesium carbonate was studied by the photoconductivity study. The second harmonic generation (SHG) for the prepared γ-glycine single crystals was studied by using Kurtz and Perry powder technique with Nd-YAG laser. The result shows that the prepared γ-glycine single crystals exhibit enhanced second harmonic conversion efficiency and it proves that these crystals are an alternate to KDP crystal in optoelectronic devices and NLO applications.

Experimental and quantum chemical studies on SHG, Z-scan and optical limiting investigation of 2-amino-5-bromopyridinium trifluoroacetate single crystal for optoelectronic applications

The 2-amino-5-bromopyridinium trifluoroacetate (2A5BPTFA) crystal has been successfully grown by solvent slow evaporation technique. The grown crystal is found to non-centrosymmetric space group Pna21 with orthorhombic crystal system, which has been confirmed from single crystal X-ray diffraction analysis. The crystalline nature of the 2A5BPTFA is supported by powder X-ray diffraction technique. The molecular structure and different functional groups in 2A5BPTFA were confirmed by 1H, 13C NMR and FTIR spectral analyses. The intermolecular charge transfer that occurs in 2A5BPTFA molecule due to the presence of N–H⋯O and C–H⋯O hydrogen bondings have been studied by Hirshfeld surface analysis. From the UV–Vis absorption and photoluminescence spectra, the lower cutoff wavelength and emission peak are found to be 364 nm and 392 nm, respectively. In addition, the optical band gap of grown crystal has been calculated as 3.47 eV. Powder second harmonic generation efficiency of the crystal is observed to be 2.44 times greater than that of potassium dihydrogen phosphate. A positive photoconducting nature and low dielectric constant values have been obtained from photoconductivity and dielectric studies. From the Z-scan study reveals the self-defocusing nature of the grown crystal. Optical limiting study shows the optical limiting response of 2A5BPTFA crystal. In addition, the intermolecular charge transfer interactions and existence of N–H⋯O hydrogen bonding of the 2A5BPTFA have been confirmed by density functional theory methods and are discussed in detail.

A new organic nonlinear optical material: L-asparagine cetrimonium bromide single crystal for photonic applications

Abstract The new organic nonlinear optical material, L-Asparagine Cetrimonium Bromide (LACB) was synthesized by using slow evaporation method at ambient conduction. The crystallographic data was analyzed by single crystal X-ray diffraction (XRD) and crystalline perfection was studied under high resolution powder X-ray diffraction technique. The functional groups were found out by FT-IR spectroscopy and various optical parameters were performed by using UV–Vis NIR spectroscopy. In fluorescence spectrum the sharp emission peak was observed at 529 nm it reveals the green emission. The second harmonic generation efficiency was determined by the Kurtz powder method using Nd-YAG laser. The laser induced damage threshold value was found to be higher than most of the reported organic single crystals. The dielectric permittivity and dielectric loss were analyzed as a function of frequency. The photoconductivity study implies that the grown crystal has positive photoconductive nature. Different mechanical properties were analyzed by Vickers microhardness test.

Growth of high-quality organic single crystal of 2-aminopyridinium 4-nitrophenolate 4-nitrophenol (2AP4N) by a novel Rotational Sankaranarayanan–Ramasamy (RSR) method

The good quality 2-aminopyridinium 4-nitrophenolate 4-nitrophenol (2AP4N) single crystals have been grown by (i) Sankaranarayanan–Ramasamy (SR) method and (ii) Rotational Sankaranarayanan–Ramasamy (RSR) method. The effect of rotation on unidirectional crystal growth method (RSR) has been reported for the first time. The apparatus was specially designed and developed for the growth of high-quality crystals by slow cooling under rotational conditions. The high-quality crystals have been achieved under forced convection and the quality of the crystal is compared to the crystals grown under free convection conditions. The crystal structure was analyzed by single crystal X-ray diffraction (SXRD) measurement. The grown crystal was subjected to the powder X-ray diffraction (PXRD) analysis to confirm the growth direction along (0 0 1) plane. The optical quality of the grown crystals has been analyzed by UV–Vis NIR spectrophotometer. It confirms that the grown crystal is highly transparent in the visible and near IR region. The photoluminescence behaviour was recorded in the wavelength region between 450 and 700 nm. It confirms that the grown crystal has emission at 500 nm. The electro-optical properties of the grown crystal were analyzed by photoconductivity measurement and it has positive photoconductivity nature. The grown crystal has less dislocation densities as confirmed by chemical etching analysis. The mechanical strength was investigated by Vickers microhardness tester. The frequency dependent dielectric properties of the crystals were investigated. The laser damage threshold (LDT) was measured for both SR and RSR method grown crystals. The full-width at half maximum (FWHM) of high-resolution X-ray diffraction (HRXRD) curves indicate that the grown crystal has high crystalline perfection. The results obtained from the SR and RSR method grown 2AP4N crystals were compared. The RSR method grown crystal has higher optical transparency, higher photoluminescence, higher photoconductivity, higher mechanical strength, higher laser damage threshold, higher crystalline perfection, less dislocation density, low dielectric loss and low full with at half maximum (FWHM). The second harmonic generation (SHG) of 2AP4N was analyzed by Kurtz-Perry powder technique. The SHG efficiency was found to be 4.5 times that of reference KDP material. The above studies reveal that the RSR method grown crystals are more useful for device applications.

Crystal growth and characterization of γ-glycine grown from AgSO4 for nonlinear optical applications

In the present work 0.1–0.5 M proportions of silver sulphate (AgSO4) added glycine single crystals were grown by slow solvent evaporation method. The Powder XRD study confirms that the grown crystals have γ-glycine crystal structure and it crystallizes into a hexagonal structure with a non-centrosymmetric space group of P31. The dielectric constant and dielectric loss of grown crystal was carried out as a function of frequency and the results were discussed. The positive photoconducting nature of the grown crystals was studied by the photoconductivity study. Second harmonic generation (SHG) efficiency of the grown γ-glycine crystal was assessed by using Nd: YAG laser. The results confirms that the grown crystals have higher efficiency compared to the reference (KDP) crystal.

A new metal-organic nonlinear optical material: L-Asparagine Indium chloride (LAIn) for photonics application

Single crystal of l-Asparagine Indium chloride (LAIn), a new semi-organic crystal was grown by slow evaporation method with deionized water as solvent at ambient condition. The crystal structure of LAIn has been determined by single crystal X-ray diffraction and the result shows that the crystal belongs to the orthorhombic system with P212121 space group. The crystalline nature of grown crystal was analyzed by powder X-ray diffraction analysis. Optical parameters, such as absorbance, transmittance and optical band gap energy were analyzed using UV–Vis NIR transmittance data at the range of 190–800 nm. The ultraviolet (UV) emission nature of the sample was established from the sharp emission peaks in photoluminescence (PL) spectrum. The photo conductivity test exhibits that the grown crystal has positive photo conductive nature. The induced surface laser damage threshold (LDT) for the grown crystal was measured using Nd:YAG laser. The nonlinear optical efficiency of the LAIn crystal was studied using modified Kurtz-Perry powder technique. The hardness, Meyer index, yield strength and elastic stiffness constant were calculated for the grown crystal using Vickers microhardness tester. The variation of dielectric constant and dielectric loss of the grown crystals as a function of frequency has been investigated at different temperatures. The melting point and thermal stability of the LAIn single crystal have been studied by thermo gravimetric analysis and differential thermal analysis (TG/DTA).

Growth and characterization of γ-glycine single crystals for photonics and optoelectronic device applications

In this present work, MnSO4-added glycine single crystals were grown by slow solvent evaporation method. Powder XRD study confirms that the crystals grown in γ-phase and it crystallizes in hexagonal structure with a space group of P31. Differential Scanning Calorimetry study revealed that the thermal characteristics of the grown polymorph. The dielectric constant and dielectric loss of grown crystal was carried out as a function of frequency and the results were discussed. The positive photoconducting nature of the grown crystals was studied by photoconductivity study. Non-Linear Optical (NLO) productivity of grown γ-glycine crystal was measured by using Nd: YAG laser. It was found to be 1.67 times higher than that of a reference (KDP).

Optical, photoconductivity and dielectric studies of zinc sulphate added glycine crystal for photonics applications

In present studies, we have successfully grown γ-glycine single crystal in the presence of ZnSO4 as an additive by using slow solvent evaporation method. Powder X-ray Diffraction study confirms crystal grown in γ-phase and it crystallizes into a hexagonal structure with a space group of P31. UV–vis transmittance spectra was recorded for the sample to analyse the optical transparency in visible and near infrared region (NIR). In Kurtz-Perry powder test, SHG efficiency of the grown ZnSO4 added glycine crystal is found to be 3.18 times higher than reference KDP crystal. The dielectric constant and dielectric loss of ZnSO4 added glycine crystal was carried out as a function of temperature by varying the frequency and the obtained results were discussed. The photoconductivity study confirms the positive photoconducting nature of grown ZnSO4 added glycine crystal.

Study of optical and laser damage threshold in EDTA and DTPA-doped DAST single crystals

We report the influence of EDTA and DTPA on the optical and laser damage thresholds of industrially relevant 4-dimethylamino-N-methyl stilbazolium tosylate (DAST) single crystals. Single crystal X-ray diffraction and powder X-ray diffraction studies substantiate that they crystallize in monoclinic system. The dopants facilitate tuning of the refractive indices and their optical conductivity. The laser damage threshold values of EDTA and DTPA-doped DAST crystals were found to be 1.5 and 1.6 times higher than the pure DAST crystal. The voltage-dependant photoconducting studies performed at ambient conditions shows negative photoconducting nature for pure and EDTA-doped DAST crystals while positive photoconducting nature is noticed for DTPA-doped crystal. The etching studies demonstrate the quality of the doped DAST crystals is better than the pure one.