In view of the worldwide energy challenge in the 21(st) century, the technology of semiconductor-based photoelectrochemical (PEC) water splitting has received considerable attention as an alternative approach for solar energy harvesting and storage. Two-dimensional (2D) structures such as nanosheets have the potential to tap the solar energy by unlocking the functional properties at the nanoscale. Tin(ii) sulfide is a fascinating solar energy material due to its anisotropic material properties. In this manuscript, we report on exploiting the 2D structure modulated optical properties of nanocrystalline SnS thin film synthesized by chemical spray pyrolysis using ambient transport in the harvesting of solar energy. We obtained the nanostructured SnS with well-preserved dimensions and morphologies with one step processing. The work demonstrates that the intrinsically ordered SnS nanostructure on FTO coated glass can tap the incident radiation in an efficient manner. The structure-property relationship to explain the photo-response in nanocrystalline-SnS is verified experimentally and theoretically. The novel design scheme for antireflection coating along with the anisotropic properties of SnS is conceived for realizing a PEC cell. The developed PEC cell consists of a SnS photoanode which shows considerably high photocurrent density of 7 mA cm(-2) with aqueous media under AM 1.5G, 100 mW cm(-2) exposure with notably stable operation. Electrochemical impedance spectroscopy revealed that a non-ideal capacitive behavior as well as drift assisted transport across the solid-state interface is responsible for such a high photo-current density in the nanocrystalline-SnS photoanode.

Spray pyrolysed thin films of quaternary Cu2ZnSnS4 (CZTS) were successfully deposited on soda lime glass substrates at 320 °C under a non-equilibrium condition (by varying Zn, Sn and S precursor concentrations) and without additional sulfurization. The effect of deficiency and enrichment of these three elements (normalized with respect to Cu) on the film's microstrain, optical band-gap and Hall mobility was investigated. A large non-uniform microstrain of (5–6) × 10−3 and compressive nature were observed for both Zn- and Sn-enriched films from Williamson–Hall analysis of x-ray diffraction (XRD) data. However, a tensile strain of (2–3) × 10−3 was revealed in Sn-poor and S-rich samples. The optical band-gap (E g) in stoichiometric CZTS was found to be 1.45 eV and Hall mobility (μ H) in the range 87–92 cm2 V−1 s−1 was observed for S- and Zn-enriched films. The tensile nature of microstrain and inhomogeneities in E g and μ H were observed with greater magnitude due to the existence of other secondary phases, which were confirmed complementarily by FTIR spectroscopy and XRD.

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This work describesex situCu-doped SnS demonstrating a largeJph= 3.2 mA cm−2as a photocathode and enhancedVOC= 465 mV in a hetero-junction solar cell.

The role of back metal (M) contact in sprayed SnS thin film solar cells with a configuration Glass/F:SnO2/In2S3/SnS/M (M = Graphite, Cu, Mo, and Ni) was analyzed and discussed in the present study. Impedance spectroscopy was employed by incorporating constant phase elements (CPE) in the equivalent circuit to investigate the degree of inhomogeneity associated with the heterojunction and M/SnS interfaces. A best fit to Nyquist plot revealed a CPE exponent close to unity for thermally evaporated Cu, making it an ideal back contact. The Bode phase plot also exhibited a higher degree of disorders associated with other M/SnS interfaces. The evaluation scheme is useful for other emerging solar cells developed from low cost processing schemes like spray deposition, spin coating, slurry casting, electrodeposition, etc.

Tenorite CuO thin films have been synthesized via spray pyrolysis of aqueous copper(II) chloride solution followed by heat-treatment, exhibited a photocurrent density of 24 mA cm −2 at 0.25 V vs. RHE under AM 1.5G solar irradiation in alkaline electrolyte. This large photocurrent density has been attributed to a drift assisted transport of photo-generated electrons across the semiconductor/electrolyte interface in the annealed films. The tendency of photo-corrosion from the surface of CuO has been reduced substantially without any extra protective layer, simply by adding K 3 Fe(CN) 6 in the electrolyte, which acts as a sacrificial excess-electron scavenging agent. The fabricated electrode exhibited a positive onset potential at 0.25 V vs. RHE even after the electrolyte modification and a stable photocurrent density of more than 40% has been retained after 20 minutes of continuous illumination. The processed photocathode showed a solar to chemical conversion efficiency of 7.85% and 21.5% with and without using an electron scavenging agent, respectively. It holds the promise of using this photocathode in PEC energy conversion, photocatalysis and solar water splitting.In the exploration of terrestrially employable carbon-free energy sources, materials play a central role in the generation and storage of electrical as well as chemical energies. 1,2 Semiconducting materials are especially important to harvest the solar energy due to their bandgap energies matching to that of the visible photons. Photovoltaic (PV) and photoelectrochemical (PEC) methods are the two solar energy conversion modes those utilize semiconductor materials. In order to apply semiconductors in PEC applications, three important aspects must be satisfied: first, capability of providing large photocurrent density; second, a long term stability; and third, the scalability. 3 Several semiconductors, such as have been explored in the PEC applications with majority as catalysts for water splitting. The hunt for novel structure and materials design thus continues to set off the above requirements. Oxides of copper (CuO and Cu 2 O) have recently drawn special attention due to their relative abundance on the earth crust. Majority of the recently reported investigations are focused on Cu 2 O. [25][26][27][28][29][30][31][32] Due to the chemical instability and poor electron transfer, its nano-composites with other oxides or metal catalysts have been attempted. [33][34][35] On the other hand, CuO is chemically more stable than Cu 2 O but there are only few studies on the PEC response of CuO have been reported so far. 36 Among various oxides of copper (viz. Cu 2 O, CuO and Cu 4 O 3 ), tenorite CuO is a chemically stable p-type semiconductors having an indirect bandgap in the range of 1.3-1.7 eV. 37-42 This property makes CuO a promising candidate for solar to chemical energy conversion with maximum possible theoretical photocurrent density in the range of 22-35 mAcm −2 under standard AM 1.5G solar irradiance corresponding to its high and low bandgap values, ...

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