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In the present investigation, a one-step hydrothermal approach is proposed to synthesize Li+, Rb+, and In3+intercalated PW12O40 (PTA) thin films. The photoelectrochemical performance of the deposited Li3PW12O40 (Li−PTA), Rb3PW12O40 (Rb−PTA), and In3PW12O40 (In−PTA) photocathodes were investigated using a two-electrode cell configuration of FTO/Li3PW12O40/(0.1 M I−/I3−)aq./Graphite. The energy band gaps of 2.24, 2.11, and 2.13 eV were observed for the Li−PTA, Rb−PTA, and In−PTA films, respectively, as a function of Li+, Rb+, and In3+. The evolution of the spinal cubic crystal structure with increased crystallite size was observed for Rb+ intercalation within the PTA Keggin structure, which was confirmed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) revealed a modification in the surface morphology from a rod-like structure to a densely packed, uniform, and interconnected microsphere to small and large-sized microspheres for Li−PTA, Rb−PTA, and In−PTA, respectively. Compositional studies confirmed that the composing elements of Li, Rb, In, P, W, and O ions are well in accordance with their arrangement for Li+, Rb+, In3+, P5+, W6+, and O2− valence states. Furthermore, the J-V performance of the deposited photocathode shows power conversion efficiencies (PCE) of 1.25%, 3.03%, and 1.62%, as a function of the incorporation of Li+, Rb+, and In3+ ions. This work offers a one-step hydrothermal approach that is a prominent way to develop Li+, Rb+, and In3+ ions intercalated PTA, i.e., Li3PW12O40, Rb3PW12O40, and In3PW12O40 photocathodes for competent solar energy harvesting. [ABSTRACT FROM AUTHOR]

In the present report, we have reported the bismuth selenide (Bi2Se3) thin films for solar cell application. The synthesis of bismuth selenide (Bi2Se3) thin film by using modified chemical bath deposition i. e. arrested precipitation technique (APT). The Physico‐chemical properties of synthesized Bi2Se3 thin films are studied as a function of surfactants. The XRD patterns confirm the nanocrystalline nature. The SEM images reveal morphological transitions from fibrous reticulate structure to spongy balls‐like structure. The compositional analysis confirms bismuth and selenium in good stiochiometry. Optical studies show presence of a absorption in the visible range with a band gap in the range of 1.5 eV to 1.9 eV. All these results reveal that surfactant‐assisted Bi2Se3 thin film is a better candidate for PEC performance. [ABSTRACT FROM AUTHOR]

Substitution of the cation is a major focus to diminish the antisite defects and boost the photovoltaic properties of the Cu2ZnSn(S,Se)4 absorber. In the present study, a facile hydrothermal route was successfully implemented for the synthesis of Cu2Zn1−xInxSn(S,Se)4 (x = 0.0 to 0.075 M) (CZITSSe) thin films for solar cells. The morphology of the CZITSSe was engineered from nanocubes to compact well grown nanoflowers like surface morphology. The improvement in the photocurrent (Jsc) from 3.09 to 4.26 mA cm−2 associated with the photovoltage (Voc) from 386 to 556 mV and accompanying improvement in the conversion efficiency (η %) from 1.96% to 4.82% were accomplished via Indium (In3+) ion incorporation. The composition CZITSSe (x = 0.075 M) showed exemplary photoelectrochemical behavior with a highest photoconversion efficiency (PCE) of 4.82%. Further, I–V performance of the deposited photocathode shows conversion efficiency of 2.01 to 5.12% as function of Indium ions incorporation. The improvement in PCE was mainly ascribed to improved crystal quality and suitable band gap energy. The EIS analysis demonstrates that the charge transfer resistance (Rct) of the CZITSSe films was reduced with In3+ ion concentration. This work offers a one-step hydrothermal route that is a prominent way to develop an In3+ ion substituted Cu2Zn1−xInxSn(S,Se)4 photoelectrode for competent solar energy harvesting. [ABSTRACT FROM AUTHOR]

In the present work, we have synthesized tin disulphide (SnS2) thin films via a facile, low cost, single-step hydrothermal route using various surface directing agents. The SnS2 thin films were characterized for their optical, structural and morphological properties. The optical study illustrated a direct allowed type of optical transition with a bandgap in the range of 1.78 to 2.03 eV. Morphological study demonstrated the formation of hierarchical nutshell surface morphologies, when using different surfactants, having higher surface-to-volume ratios for better light absorption. The structural study revealed that nanocrystalline SnS2 thin films were formed with a pure hexagonal crystal structure with crystallite size ranging between 12.24 and 19.79 nm. Compositional analysis confirmed the formation of pure and stoichiometric SnS2 thin films. Finally, we carefully analyzed the photoresponse properties of the as synthesized and surfactant-assisted SnS2 thin films with the help of a standard two-electrode system on an electrochemical workstation where SnS2 thin films acted as the working electrode and graphite acted as the counter electrode. Photocurrent (Jsc) was enhanced with the use of the surface directing agents from 0.24 to 0.96 mA cm2 allied with a photovoltage (Voc) from 416 to 610.2 mV. The highest photoelectric conversion efficiency was obtained for the Triton X-100 assisted SnS2 photoanode and it was 0.83%. EIS performance of SnS2 thin films synthesized with surfactants demonstrated reduced charge transfer resistance (Rct), which supports the PEC (photoelectrochemical) performance. [ABSTRACT FROM AUTHOR]

The current study focused on fabrication of phosphomolybdic acid (H3PMo12O40) (PMA) and cesium intercalated phosphomolybdic acid (Cs3PMo12O40) (Cs-PMA) thin films via simplistic and low-cost hydrothermal reaction. We explored comparative analysis of PMA and Cs+ intercalated PMA for their optoelectronic and photoelectrochemical properties. UV–Visible absorption study demonstrates the decrement in band gap energy from 2.37 to 2.22 eV, forming a well-grown cubic crystal structure with alteration in the surface morphology. XPS analysis validates the presence of Cs, P, Mo, and O in its valence states of +1, +5, +6, and − 2, respectively. The p-type semiconducting nature of Cs3PMo12O40 films was confirmed by thermoelectric measurement. The photoelectrochemical solar cell exhibited a conversion efficiency (η) of 0.21 and 0.82% for PMA and Cs-PMA photocathode, respectively. The photoelectrochemical performance of PMA and Cs-PMA photocathodes was thoroughly described using Nyquist plots and a circuit model of the electron impedance spectra. The enhancement in the conversion efficiency is attributed to compact nanospheres like microstructures with improved crystallinity as well as optimal band gap energy of Cs-PMA photocathode. [ABSTRACT FROM AUTHOR]