Surface Photovoltage Properties Research Articles

Synthesis and characterization of urchin-like CuO nanorod/TiCu-based metallic glass core-shell powders with surface photovoltage performance

The core-shell urchin-like powders (i.e. the microsized core composed of the residual metallic glass matrix powders and short CuO nanorod as the shell) were obtained through selective hydrothermal dealloying and annealed oxidation methods. TiCu-based metallic glass powders were used as precursors. Furthermore, the morphology and photoelectric conversion property of urchin-like CuO nanorod/metallic matrix powders were comprehensively investigated. These core-shell powders possess considerable surface photovoltage properties, and the sample annealed at 500 °C in air exhibits optimal surface photoelectric responses in visible light range (~600 nm). The surface photovoltage property was determined by the synergistic effect of crystallinity and surface morphology for the CuO phase. This study provides a strategy for in-situ synthesis of novel micro-nano-sized core-shell functional materials using facile dealloying and annealing of multiple-component alloys. The advantage of obtained products will further accelerate their applications in the green industry since this kind of micro-nano-sized powder material is easy to separate and recycle.

Potentiostatic and galvanostatic two-step electrodeposition of semiconductor Cu2O films and its photovoltaic application

Electrodeposition is of great interest for a large number of applications, especially in low-cost thin film solar cells. In this work, Cu2O films were electrodeposited firstly with potentiostatic and galvanostatic modes, respectively. The trends of current density and applied potential were systematically studied in the deposition process, and some drawbacks were revealed within the two deposition modes. In order to remove the drawbacks, potentiostatic and galvanostatic two-step electrodeposition was developed to prepare Cu2O films. The optical absorption and surface photovoltage properties of the prepared Cu2O films were studied. Finally, the two-step electrodeposition was used to construct Cu2O based solar cells. The two-step electrodeposition will be an optimized method to construct high-quality semiconductor film based solar cells.

3D Framework and Supramolecular Structures Assembly from a Carboxyphosphonic Acid and Transition Metals: Sensing of Nitro Compounds and Surface Photovoltage Properties

AbstractThree new metal carboxyphosphonates with 3D framework and supramolecular structures, namely, [Zn(H4L)2] (1), [Cu2(HL)(H2O)2] (2) and [NH(CH2)4NH]0.5[Cu(H3L)] (3) (H5L=4‐HOOC‐C6H4‐CH2N‐(CH2PO3H2)2), have been synthesized under hydrothermal conditions. For compound 1, {ZnO6} and {CPO3} polyhedra are interconnected into a 2D layer via corner‐sharing, which is further assembled into a 3D supramolecular structure through π‐π stacking interactions. Compound 2 exhibits a 3D framework structure. The interconnection of {CuO4N}, {CuO5} polyhedra and {CPO3} tetrahedra via corner‐sharing forms a 2D inorganic layer. These inorganic layers are further linked via the organic backbone {−C6H4CH2N(CH2)2−} of the carboxyphosphonate ligands, generating a 3D framework structure. In compound 3, two {CuO4N} polyhedra and four {CPO3} tetrahedra are interconnected into a unit, and then these units are further connected into a 1D infinite chain via corner‐sharing. Neighboring chains are assembled into a 2D layered structure through hydrogen bond interactions between the nitrogen atoms from piperazine and uncoordinated phosphonate oxygen atoms. Then, such layers are further assembled into a 3D supramolecular network via interlayer hydrogen bonds. Compound 1 has been realized for the sensitive sensing of 4‐nitrophenol (4‐NP) by luminescence quenching method in the liquid phase. Surface photovoltage properties of compounds 2 and 3 have been investigated.

Enhancing visible light photocatalytic and photocharge separation of (BiO)2CO3 plate via dramatic I− ions doping effect

Novel I− ions doped (BiO)2CO3 (I-(BiO)2CO3) photocatalysts were successfully synthesized via a facile chemical precipitation method. Under visible light (λ>400nm), I-(BiO)2CO3 displayed much higher activity for rhodamine B and dichlorophenol degradation than the undoped (BiO)2CO3. The pseudo-first-order rate constant kapp of RhB degradation over 15.0% I-(BiO)2CO3 was 0.54h−1, which is 11.3 times higher than that of (BiO)2CO3. The doped I− ions formed an impurity level on the top of valence band of (BiO)2CO3 and induced much more visible light to be absorbed. The enhanced photocurrent and surface photovoltage properties were detected, which strongly ensures the efficient separation of electrons and holes in I-(BiO)2CO3 system under visible light. It provides a facile way to improve the photocatalytic activity of the wide-band-gap (BiO)2CO3 via intense doping effect of I− ions.

Photoluminescence and surface photovoltage properties of ZnSe nanoribbons

ZnSe nanoribbons were synthesized with chemical vapor deposition route. The excitation power-dependent photoluminescence and surface photovoltage (SPV) techniques were used to study the optoelectronic properties of the as-grown ZnSe nanoribbons. Three deep defect (DD)-related emission bands, respectively, centered at 623nm (DD1), 563nm (DD2) and 525nm (DD3), emerge orderly with increasing the excitation power, which is attributed to the saturation of the DD states from deeper to shallower level. The SPV spectrum and the corresponding phase spectrum show that DD1 mainly acts as recombination center, while DD2 and DD3 can act as both the recombination center and electron traps. The influence of the trapping electrons on the SPV response dynamic was studied with transient SPV.

A study on the surface photovoltage property of flower-like nanobelt film

The microstructure and photoelectric response property of a Zr-doped titanate nanobelt film synthesized by hydrothermal-dealloying of Ti-based metallic glass-forming alloy are studied. A dense and uniform flower-like nanobelt film grows on the surface of the Ti-based alloy substrate during a hydrothermal process. Furthermore, the nanobelt film shows prompt and reversible surface photo-voltage response with irradiation wavelength in the range of 300–350nm. This work may provide a facile way to fabricate flexible shaped nanomaterial films with unique photoelectric properties using alloy as precursors.

Experimental, characteristic evidence and surface photovoltage properties of a series of Cu/Mn complexes with bipyrazolyl-pyridine and different spanning dicarboxylate

By introduction of different spanning flexible dicarboxylate as auxiliary ligands, novel complexes with N-heterocyclic ligand, [Cu(H2L)(ox)]·2H2O (1), [Cu2(HL)2(Hglu)]·2CH3OH·H2O (2), and [Mn(H2L)(ad)]·H2ad (3) (H2L=2,6-di-(5-methyl-1H-pyrazol-3-yl)pyridine, ox=oxalic acid, glu=glutaric acid, ad=adipic acid) are synthesized with hydrothermal method. Structural analysis reveals that the coordination modes of metal center in these complexes are various, in complexes 1 and 2, Cu(II) atom is five-coordinated to form a distorted square pyramid geometry. While in complex 3, Mn(II) atom is six-coordination mode, forming a distorted octahedron. In complexes 1–3, the N-heterocyclic ligand is coordinated with one or two metal centers. While in complexes 2 and 3, two metal centers are connected by bridging coordination fashions of flexible dicarboxylate and N-heterocyclic ligands, which are different from those in complex 1. In addition, the surface electron behaviors of complexes 1 and 3 have also been studied. The results show that the surface photovoltage (SPV) response signals increase when the positive electric field enhances in the range of 300–800nm. This result reveals that these complexes have the potential characterization of being able to trap photogenerated electron or hole, enhancing the separation extent and restrain the recombination of the photogenerated electron and hole.

Synthesis, structures, surface photovoltage and luminescence properties of two new nickel(ii) carboxyphosphonates with a 3D framework structure

Two new 3D nickel(ii) carboxyphosphonates 1 and 2 were synthesized under hydrothermal conditions. The surface photovoltage and luminescent properties were studied.

Self-assembled synthesis and surface photovoltage properties of polyhedron-constructed micrometer solid sphere and hollow-sphere In2S3

Novel solid/hollow-sphere In2S3 materials composed of polyhedra have been synthesized, and their photoelectric properties were investigated by SPS.

Synthesis, structure, and surface photovoltage property of two new cobalt (II) phosphonates with 2D layered structure

Two new cobalt phosphonates, [enH2]0.5[Co(HL)(H2O)]·H2O (1) and [Co2(HL)(H2L)2]·2NH(CH3)2·3H2O (2) (H3L=2-hydroxyphosphonoacetic acid; en=ethylenediamine), have been synthesized under hydrothermal conditions and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. For compound 1, Co(II) atoms are octahedrally coordinated. The CoO6 octahedra and CPO3 tetrahedra are linked by HL2− into a 2D layered structure in the bc-plane. The ethylenediamine molecules and solvate water molecules are located between two adjacent layers. The structure of compound 2 composed of Co1O6 and Co2O6 octahedra via bridging phosphonate ligands leads to a 2D layered structure with one-dimensional channel system along c-axis direction. The dimethylamine molecules and solvate water molecules are located between two adjacent layers. The surface photovoltage properties of compounds 1 and 2 have also been studied.

Syntheses, crystal structures, surface photovoltage, luminescence and molecular recognition properties of zinc(ii) and iron(ii) carboxyphosphonates with 2D and 3D supramolecular structures

Four new transition metal carboxyphosphonates with 2D and 3D supramolecular structures, namely, Fe2[(HL)(H2O)] (1), Fe(H4L)2 (2), Zn(H3L) (3) and Zn2(HL) (4) (H5L = 4-HO2C–C6H4–CH2N(CH2PO3H2)2), have been synthesized under hydrothermal conditions. For compound 1, {FeO5N} and {CPO3} polyhedra are interconnected into a 2D layer in the bc-plane via corner-sharing. Then the adjacent layers are further assembled into a 3D supramolecular structure through π–π stacking interactions. Compound 2 shows a 3D supramolecular structure. {FeO6} and {CPO3} polyhedra are interconnected into a 2D layer in the bc-plane via corner-sharing, which is further linked through π–π stacking interactions to form a 3D supramolecular structure. The overall structure of compound 3 can be described as a 2D supramolecular structure. The {ZnO4} polyhedra are interconnected by {CPO3} tetrahedra via corner-sharing to form a 1D chain. These neighboring metal phosphonate chains are connected through hydrogen bonding interactions to give rise to a 2D supramolecular structure in the ac-plane. In compound 4, {ZnO3N} and {ZnO4} polyhedra are interconnected by {CPO3} tetrahedra via corner-sharing and edge-sharing to form a 2D inorganic layer in the bc-plane, which is further linked through π–π stacking interactions to form a 3D supramolecular structure. The surface photovoltage properties of compounds 1–2 and luminescence properties of compounds 3–4 have been investigated. More interestingly, compound 4 is selective for sensing DMF and acetone.

Surface photovoltage properties of self-assembled CdSe quantum dots arrays fabricated by slow evaporation approach

Densely packed and highly ordered CdSe quantum dots (QDs) arrays were prepared through a slow evaporation route; to study the photo-generated charges property of ordered CdSe QDs arrays, illumination induced charge separation in the CdSe QDs arrays were investigated through surface photovoltage (SPV) technology based on lock in amplifier. The significantly enhanced SPV signal of CdSe QDs arrays after post-annealing treatment could be attributed to the greatly increased escape of holes from CdSe QDs surface, as well as the decreased the inter nanocrystal distance. Moreover, much faster excess holes dominates in the frequency range of 30 Hz and 200 Hz, which results in the positive charging of the CdSe QDs arrays near the surface. Our results give a guide for its practical photoelectric applications based on nanocrystals.

Synthesis, structure, and surface photovoltage properties of a series of novel d7–d10 metal complexes with pincer N-heterocycle ligands

Novel d7–d10 complexes Cu(bpz*eaT)(SCN)2 (1), Ni(bpz*eaT)(SCN)2 (2), Co(bpz*eaT)((SCN)2 (3), [Ni(bpz*eaT)(N3)]·H2O (4) and Co(bpz*eaT)(N3) (5) (bpz*eaT: 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-diethylamino-1,3,5-triazine) were synthesized by the reaction of a metal salt (CuCl2·2H2O, NiCl2·6H2O, CoCl2·6H2O or Co(CH3COO)2·4H2O), pincer N-heterocyclic ligands and KSCN or NaN3 in either acetonitrile or a mixed solution at different temperatures. The structures of these complexes were characterized by elemental analysis, IR and UV-Vis spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analyses (TG) and single-crystal diffraction analysis. Structural analysis reveals that the metal atoms (Cu and Co) in complexes 1, 3 and 5 are in a five-coordination mode, forming distorted square pyramid geometries with N5 donors; Ni atoms in the complexes 2 and 4 are in a six-coordination mode, forming slightly distorted octahedra with the set of N5S and N6 cores, respectively. In complexes 1–5, the auxiliary N-donor monodentate ligands were only connected with one metal center. In complexes 2 and 4, the two metal centers were connected by bridging coordinated SCN− and N3−, which were different from those in complexes 1, 3 and 5. In addition, surface photovoltage properties of the five complexes have also been studied and discussed in detail. Surface photovoltage spectra (SPS) of the complexes 1–5 show that the surface photovoltage (SPV) response signals increase when the positive electric field is enhanced in the range of 300–800 nm. The results show that these complexes possess potential p-type semiconductor properties and their uses may be extended to semiconductor materials.

Mixed-solvothermal synthesis, structures, luminescent and surface photovoltage properties of four new transition metal diphosphonates with a 3D supramolecular structure

Four new transition metal(II) diphosphonates with a 3D supramolecular structure, M(hedpH2)3·3NH2(CH3)2NH(CH3)3·3H2O (M = Mn (1), Co (2), Ni (3), Zn (4); hedpH4 = 1-hydroxyethylidenediphosphonate acid) have been synthesized under mixed-solvothermal conditions and structurally characterized. Compounds 1–4 are isomorphous and adopt a three-dimensional supramolecular network structure containing {M(hedpH2)3}4− cluster units. The interconnection of {MO6} and {CPO3} polyhedra via corner-sharing forms a {M(hedpH2)3}4− cluster, and these isolated clusters are extended by hydrogen bonds to form a two-dimensional layer structure, which are further connected through hydrogen bonding interactions to give rise to a 3D supramolecular structure. Surface photovoltage spectroscopy (SPS) of compounds 1–4 indicates that it possesses positive SPV response in the range of 300–600 nm and shows p-type semiconductor characteristic. Luminescence properties of the four compounds have also been studied.

Synthesis, crystal structures, and surface photovoltage properties of four new metal diphosphonates based on the mixed ligands

By introduction of 2,2′-bipy or 1,10-phen as a second organic ligand, four new metal diphosphonates with mixed ligands, namely, [M(2,2′-bipy)(hedpH3)2]·H2O (M = Co (1), Ni (2)), [M(1,10-phen)(hedpH3)2]·H2O (M = Co (3), Ni (4)) (hedpH4 = 1-hydroxyethylidenediphosphonic acid, 2,2′-bipy = 2,2′-bipyridine, 1,10-phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions. Compounds 1 and 2 are isostructural and adopt a 2D supramolecular network. Each {MN2O4} octahedron and four {CPO3} tetrahedra are interconnected into a {M(2,2′-bipy)(hedpH3)2} (M = Co (1), Ni (2)) unit via corner-sharing. These isolated units are interlinked through hydrogen bonding interactions to form 1D infinite chains, which are further assembled into a 2D supramolecular network through π–π stacking interactions. Compounds 3 and 4 are also isostructural and show a 1D double chain structure constructed from {M(1,10-phen)(hedpH3)2} (M = Co (3), Ni (4)) units. In compounds 3 and 4, the {M(1,10-phen)(hedpH3)2} units are linked to each other through hydrogen bonds to form a 1D infinite chain and then these 1D chains are further extended into 1D double chains by π–π stacking interactions. The surface photovoltage properties of compounds 1–4 have been investigated.

Four Novel Oxomolybdenum-Organodiphosphonate Hybrids in the Presence of Cu(II)–Organonitrogen Building Blocks: Synthesis, Crystal Structures, and Surface Photovoltage Properties

Four novel organic–inorganic hybrid materials of the copper(II)–molybdophosphonate family, [Cu(1,10-phen)Mo2O5(H2O)(hedp)] (1), [{Cu(1,10-phen)}{Cu(1,10-phen)(H2O)}MoO2(hedpH)2]·H2O (2), [Cu(1,10-phen)Mo0.5O(hedpH)] (3), and [{Cu(2,2′-bipy)(H2O)}MoO2(hedp)]·2H2O (4) (hedpH4 = 1-hydroxyethylidenediphosphonate, 2,2′-bipy = 2,2′-bipyridine, 1,10-phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions. In compound 1, the interconnection of {MoO6}, {CuN2O2}, and {CPO3} polyhedra leads to a 2D layer through edge-sharing and corner-sharing, and such layers are further assembled into a 3D supramolecular structure by π–π stacking interactions. Compound 2 contains a 1D chain built up from {MoO6}, {CuN2O3}, and {CPO3} polyhedra, and then these 1D chains are further extended into 2D supramolecular layer by hydrogen bonding interactions. Such neighboring layers are further assembled into a 3D supramolecular structure via the π–π stacking interactions. For compound 3, the [{Cu(1,10-phen)}2MoO2(...

Ultrasound assisted quick synthesis of square-brick-like porous CuO and optical properties

Square-brick-like CuC2O4 intermediate was synthesized quickly by an ultrasound and microwave assisted solution route in the presence of sodium dodecyl benzene sulfonate (SDBS) surfactant using CuCl2 and K2C2O4 as raw materials. The CuC2O4 was transformed into CuO with a preserved morphology by heating at 300°C for 2h. The products were characterized by XRD, TG-DTA, XPS, SEM, TEM, HRTEM and N2 adsorption–desorption measurement. The light harvesting capability, photoluminescence and surface photovoltage properties of the CuO were investigated. The width and thickness of the obtained porous CuO square bricks are ca. 0.5–1μm and 200nm, respectively. Its average primary particle size is 12nm. The formation mechanism of this square-brick-like CuO was investigated on the basis of series of controlling experiments. The results show that SDBS, C2O42− and ultrasonic processing play important roles in the formation of this square-brick-like morphology.

Surface photovoltage property of magnesium ferrite/hematite heterostructured hollow nanospheres prepared with one-pot strategy

Magnesium ferrite/hematite heterostructured hollow nanospheres were successfully fabricated via a facile solvothermal method. The products were well characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, UV–vis absorption spectroscopy and surface photovoltage spectroscopy. From the absorption edge in the UV–vis absorption spectrum of MgFe2O4/α-Fe2O3 hollow nanospheres, an optical band-gap energy of about 1.986eV was estimated. Furthermore, it was observed that the heterostructured hollow nanospheres presented a remarkable surface photovoltage response in UV and visible spectral region, which was attributed to the effective formation of chemical interface between the two crystalline phases of MgFe2O4 and α-Fe2O3.

Synthesis, structures and surface photovoltage properties of four novel metal phosphonates with a 3D supramolecular structure

By introduction of oxalate as a second organic ligand, four novel metal phosphonates with a 3D supramolecular structure, namely, M1.5(H2O)[(H2L)(C2O4)0.5] (M = Fe (1), Co (2), Zn (3)) and Cu1.5[(H2L)(C2O4)0.5] (4) (H4L = C5H4NCH2CH(OH)(PO3H2)2), have been synthesized under hydrothermal conditions. Compounds 1–3 are isostructural and adopt a three-dimensional supramolecular structure. Every two {M(1)O5} polyhedra are interconnected by {CPO3} tetrahedra to form a unit and these units are linked by {M(2)O6} octahedra to form a 1D chain by corner-sharing down the c-axis. Such 1D infinite chains are cross-linked via oxalate anions into a 2D layer, which are further connected through hydrogen bonding interactions to give rise to a 3D supramolecular structure. The overall structure of compound 4 is similar to that of compounds 1–3 except that the {M(2)O6} octahedra are replaced by {Cu(2)O4} planar squares. Surface photovoltage properties of the four compounds have also been studied.

Synthesis, crystal structure and surface photo-electric property of a series of Co(II) coordination polymers and supramolecules

Four new Co(II) coordination complexes, [Co( o-phta)(pz) 2] n 1, [Co(PTA) 2(Imh) 2]·(HPTA)·H 2O 2, {[Co(pdc) 2(H 2O)]·(ppz)·2H 2O} n 3, [K 2Co 2(ox)(btec)(CH 3OH) 2] n 4, (H 2phta = o-phthalic acid, pz = pyrazole, HPTA = p-toluic acid, ppz = piperazine, Imh = imidazole, H 2pdc = pyridine-2,5-dicarboxylic acid, H 2(ox) = oxalic acid, H 4btec = 1,2,4,5-benzenetetracarboxylic acid), were hydrothermally synthesized and characterized by X-ray single crystal diffraction, IR, UV–Vis absorption spectrum, TG analysis and elemental analysis. The surface photovoltage properties of the four Co(II) complexes were investigated by the surface photovoltage spectroscopy (SPS). The structural analyses indicate that complexes 1 and 3 are 1D coordination polymers and complex 2 is a mononuclear molecular complex. Complexes 1, 2 and 3 are connected into 2D supramolecules by hydrogen bonds, respectively. Complex 4 is a coordination polymer with 3D structure, exhibiting a 4-nodal(4,5,6,12)-connected topology with a Schläfli symbol of (4 10) 2(4 24·6 32·8 10)(4 5·6) 2(4 9·6 5·8). The results of SPS show the four complexes exhibit obvious photovoltaic responses in 300–800 nm, which indicates they all possess photo-electric conversion properties. By the comparative analysis of the SPS, it is found that structure of the complex, species of ligand and coordination micro-environment of the Co(II) ion affect the SPS. The relationships between SPS and UV–Vis absorption spectra are discussed.