The progress of single crystal followed by C$_4$H$_6$O$_6$ (tartaric acid) and BaCl$_2$ (barium chloride) (TABC; third order nonlinear optics semi-organic) was synthesized with slow evaporation method using distilled water at room temperature. TABC single crystal was introduced into various characterizations like X-ray diffraction to determine inter atomic cell parameter values. The samples are crystalline structure of monoclinic, which have space group of P$_2$. The functional groups of the current material are identified using FT-IR spectrum. Optical parameters like transparency, energy bandgap and Urbach energy have been determined using UV–vis–NIR spectrum. The thermal stability of the material was investigated by differential scanning calorimeter analysis. The mechanical property was studied using Vickers microhardness test. The surface morphology of the material was determined by scanning electron microscope technique. The change in dielectric behaviour of TABC with respect to the function of frequency at various temperatures has been keenly absorbed and discussed. The third-order nonlinear optical parameters were measured using Z-scan analyses.

L-threonine ammonium bromide (LTAB) is a significant nonlinear optical (NLO) material. The crystal has been grown by the slow evaporation technique (SET). Ammonium bromide has properties, which are that of chiral molecules and zwitterions environmental benefits due to advance NLO properties of LTAB. L-threonine-doped ammonium bromide crystals are grown using SET at ambient temperature. In this study, the unit cell factors are derived from X-ray diffraction (XRD) studies. The powder XRD spectra suggests the formation of orthorhombic crystal system. Fourier transform infrared spectroscopy (FTIR) analysis depicts the different functional groups offered in the grown crystals. The study of optical transmittance was done by crystals utilizing ultraviolet, visible, spectral analytical methods. Further, the minimum cutoff wavelength of the grown crystal has been recognized as 220 nm. The overall result of the second harmonic generation (SHG) efficiency is depicted higher and nearly around LTAB obtained crystal which is greater than potassium dihydrogen phosphate (KDP). It proves the potential application of LTAB crystal in optoelectronic industries.

In this study, TiO$_2$ nanorods (NRs) have been grown on the layer of P$_{25}$ TiO$_2$ nanoparticles (NPs) coated on the fluorine-doped tin oxide substrate and served as photoanode in dye-sensitized solar cell (DSSC). Natural dyes which contain anthocyanidins (water-soluble flavonoids) have been extracted from beetroot, grapes and red cabbage and have been used as a sensitizer in the solar cell. The decorated photoanode with TiO$_2$(NR)/TiO$_2$(NP) nanocomposites has been fabricated, and used natural dyes as sensitizer in DSSC. It is found that, the proposed cells have given the maximum photoconversion efficiency of 7.35, 6.84 and 7.04% for beetroot, grapes and red cabbage. The fill factor, open circuit voltage and short circuit current are 0.564, 0.4932 V and 5.595 mA cm$^{–2}$ for beetroot, 0.153, 0.326 V and 3.925 mA cm$^{–2}$ for grapes and 0.2577, 0.413 V and 4.8879 mA cm$^{–2}$ for red cabbage, respectively.