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Ternary Cu 2 SnS 3 (CTS) is an attractive nontoxic and earth-abundant absorber material with suitable optoelectronic properties for cost-effective photoelectrochemical applications. Herein, we report the synthesis of high-quality CTS nanoparticles (NPs) using a low-cost facile hot injection route, which is a very simple and nontoxic synthesis method. The structural, morphological, optoelectronic, and photoelectrochemical (PEC) properties and heterojunction band alignment of the as-synthesized CTS NPs have been systematically characterized using various state-of-the-art experimental techniques and atomistic first-principles density functional theory (DFT) calculations. The phase-pure CTS NPs confirmed by X-ray diffraction (XRD) and Raman spectroscopy analyses have an optical band gap of 1.1 eV and exhibit a random distribution of uniform spherical particles with size of approximately 15–25 nm as determined from high-resolution transmission electron microscopy (HR-TEM) images. The CTS photocathode exhibits excellent photoelectrochemical properties with PCE of 0.55% (fill factor (FF) = 0.26 and open circuit voltage (Voc) = 0.54 V) and photocurrent density of −3.95 mA/cm 2 under AM 1.5 illumination (100 mW/cm 2 ). Additionally, the PEC activities of CdS and ZnS NPs are investigated as possible photoanodes to create a heterojunction with CTS to enhance the PEC activity. CdS is demonstrated to exhibit a higher current density than ZnS, indicating that it is a better photoanode material to form a heterojunction with CTS. Consistently, we predict a staggered type-II band alignment at the CTS/CdS interface with a small conduction band offset (CBO) of 0.08 eV compared to a straddling type-I band alignment at the CTS/ZnS interface with a CBO of 0.29 eV. The observed small CBO at the type-II band aligned CTS/CdS interface points to efficient charge carrier separation and transport across the interface, which are necessary to achieve enhanced PEC activity. The facile CTS synthesis, PEC measurements, and heterojunction band alignment results provide a promising approach for fabricating next-generation Cu-based light-absorbing materials for efficient photoelectrochemical applications.

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Inorganic metal halide perovskites CsPbX3 (X = Cl, Br, and I) has achieved extensive attention in recent years for photovoltaics because of their unique properties like tunable band gap, high charge carrier mobility, high absorption coefficient, etc. and which makes it suitable for optoelectronic applications. In this work, we have reported a facile synthesis method of inorganic CsPbBr3 nanoparticles (NPs) at room temperature using cesium bromide (CsBr) as a Cs source, lead bromide (PbBr2) as Br source, oleic acid, and Oleylamine as capping ligands. Nucleation starts immediately after the injection of a precursor solution into the toluene. Synthesis of CsPbBr3 NPs was confirmed by X-Ray diffraction pattern, UV-Visible spectroscopy, photoluminescence (PL), scanning electron microscopy (SEM), and atomic force microscopy (AFM). X-ray diffraction pattern reveals mainly the monoclinic crystal structure of CsPbBr3 NPs. The UV-Vis absorption spectra and PL spectra show a strong absorption peak at 509 nm, emission peak at 505 nm, and the band gap of CsPbBr3 to be 2.2 eV. The synthesized CsPbBr3 exhibit regular cuboid like structure with a particle size of approximately 400-500 nm. The surface roughness morphology of CsPbBr3 NPs was studied using AFM, and it shows the roughness of the CsPbBr3 films was around 260 nm. These results provide a facile synthesis method, and CsPbBr3 NPs are a suitable candidate for the optoelectronic and photovoltaic device's application.

In this study, we report the synthesis and characterization of CdSe nanocrystals (NC's) by facile hot injection (HI) method. The formation of CdSe NC's was confirmed by X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The optical properties were analyzed by UV-visible and photoluminescence (PL) spectroscopy shows an excitonic peak at 617 nm in PL spectra corresponds to the band gap of  2 eV favourable for optoelectronic device applications. The Photoelectrochemical (PEC) performance of CdSe thin film prepared by spin coating method demonstrates a rise of photocurrent density (Jsc = 0.081 µAcm -2 ) after illumination. The Mott-Schottky (MS) and electrochemical impedance spectroscopy (EIS) measurements were further carried out to understand intrinsic properties namely the type of conductivity, flat band potential, charge carrier density (ND), charge transfer resistance, and recombination lifetime. The n-type conductivity, the charge carrier density of ND = 1.292 x 10 16 cm -3 , and recombination lifetime of 32.4 µs suggest the ideal behaviour of CdSe NC's for device quality photoelectrodes.

We report room temperature synthesis technique for the formamidinium lead iodide (FAPbI 3 ) perovskite. The low-cost sequential room temperature chemical synthesis technique resulted in formation of α-phase FAPbI 3 , suitable for solar cell absorber application. The chemical precursors formamidine acetate (CH 4 N 2 •xC 2 H 4 O 2 ) and lead iodide (PbI 2 ) were used in the process. The drop casted and spin coated films of FAPbI 3 on soda-lime glass and were then annealed at temperature of 80 °C. The FAPbI 3 materials films were characterized by X-ray diffraction, UV-Visible spectroscopy, photoluminescence (PL) measurements, and transmission electron microscopic (TEM) measurement. The X-ray diffraction pattern confirms α-phase of FAPbI 3 perovskite. The crystallite size as calculated from x-ray diffraction was found to be 40 nm corresponding to (001) peak. UV-Visible analysis shown broad absorption with bandgap value of 1.55 eV. The PL analysis show emission peak at 727 nm with estimated bandgap to be a 1.57 eV, in agreement with the UV-Visible spectroscopy. TEM analysis confirms the crystalline phase of FAPbI 3 material and the inter-planar spacing was deduced to be 0.62 nm. We conclude successful synthesis of FAPbI 3 perovskite with desirable properties in α-phase composition of FAPbI 3 that are suitable for solar cell application.

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