A novel and unique understanding pertaining to the synthesis of Cu(1.8)S and CuS in bulk was achieved from the analysis of the products of the Cu-Tu precursors, with Cl(-), NO(3)(-), and SO(4)(2-) as the counteranions, in ethylene glycol. [Cu(4)(tu)(9)](NO(3))(4)·4H(2)O always yielded CuS whether the dissociation was carried out in ethylene glycol in the presence of air or argon or under solvothermal conditions. Cu(1.8)S was the only product when [Cu(tu)(3)]Cl was dissociated in air as well as in flowing argon in ethylene glycol. A mixture of Cu(1.8)S and CuS was formed from the chloride ion containing precursor when dissociated solvothermally. [Cu(2)(tu)(6)]SO(4)·H(2)O yielded a mixture of CuS and Cu(1.8)S on dissociation in the presence of air and argon, as well as under solvothermal conditions. The oxidizing power of the anions Cl(-), SO(4)(2-), and NO(3)(-), present in the precursor, greatly determined the extent of formation of Cu(1.8)S and CuS. While Cu(1.8)S showed hexagonal plate like morphology, flower like morphology was observed for CuS in the SEM images. In the mixed phase, Cu(1.8)S + CuS, both these morphologies were present. Cu(1.8)S and CuS showed scattering resonances at 470 cm(-1) and 474 cm(-1), respectively, in the Raman spectrum. Magnetization measurements at room temperature revealed diamagnetic behavior for Cu(1.8)S indicating the presence of +1 oxidation state for copper. Weak paramagnetic behavior was observed for CuS with χ(M) value of 1.198 × 10(-3) emu/mol at 300 K. Both Cu(1.8)S and CuS showed similar emission behavior in the photoluminescence spectrum with band positions centered at around 387, 390, 401, 423, and 440 nm. The origin of photoluminescence in these two copper sulfides remains elusive.

With the capability to manipulate the built‐in field in solar cells, ferroelectricity is found to be a promising attribute for harvesting solar energy in solar cell devices by influencing associated device parameters. Researchers have devoted themselves to the exploration of ferroelectric materials that simultaneously possess strong light absorption and good electric transport properties for a long time. Here, it is presented a novel and facile approach of combining state‐of‐art light absorption and electric transport properties with ferroelectricity by the incorporation of room temperature 1D ferroelectric perovskite with 3D organic–inorganic hybrid perovskite (OIHP). The 1D/3D mixed OIHP films are found to exhibit evident ferroelectric properties. It is notable that the poling of the 1D/3D mixed ferroelectric OIHP solar cell can increase the average Voc can be increased from 1.13 to 1.16 V, the average PCE from 20.7% to 21.5%. A maximum power conversion efficiency of 22.7%, along with an enhanced fill factor of over 80% and open‐circuit voltage of 1.19 V, can be achieved in the champion device. The enhancement is by virtue of reduced surface recombination by ferroelectricity‐induced modification of the built‐in field. The maximum power point tracking measurement substantiates the retention of ferroelectric‐polarization during the continued operation.

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Two-dimensional (2D) perovskite materials are a promising platform to construct high performance photodetectors due to their novel structure, high stability, resistance to ion migration and decent light harvesting ability.

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Highly crystalline Cu(9)S(5) (Cu(1.8)S), CuSe, PbS, and PbSe are obtained by reacting the elements in 2-mercaptoethanol as the solvent for 24 h at room temperature. The elemental reactions of copper and lead with sulfur in ethylene glycol were successful, yielding CuS and PbS, respectively. Metal sulfide formation was not observed using dimercaptoethane.

Reacting thiourea precursors of the respective metals in ethyleneglycol for few hours, orthorhombic Cu3SnS4 and Ni2+, Co2+ and Sb3+ substituted quaternary compositions has been synthesised and characterized thoroughly.