Strong photo-response in a flip-chip nanowire p-Cu2O/n-ZnO junction
ABSTRACT Cu(2)O nanoneedles are synthesized on a copper substrate by a simple anodization and reducing ambient annealing protocol. ZnO nanorods are grown on ITO coated glass by a low temperature chemical route. The electronic and photo-response properties of the p-Cu(2)O/n-ZnO flip-chip heterojunction are then studied and analyzed. We show that the I-V characteristic is rectifying and the junction exhibits a good photoresponse (∼120% under 1 V reverse bias) under AM 1.5 (1 Sun) illumination. This nano-heterojunction photo-response is far stronger as compared to that of a pulsed laser deposited thin film p-Cu(2)O/n-ZnO heterojunction, which can be attributed to higher junction area in the former case.
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ABSTRACT: Zinc oxide (ZnO) nanorods are grown hierarchically on cuprous oxide (Cu2O) nanoneedles to form a Cu2O/ZnO hetero-nanobrush assembly. This increases the overall aspect ratio, which helps to enhance the field emission properties of the system. Also, the charge separation and transport are facilitated because of the multiple p-n junctions formed at p-Cu2O/n-ZnO interfaces and quasi-1-D structures of both the materials, respectively. This helps to significantly enhance the photocatalytic properties. As compared to only Cu2O nanoneedles, the Cu2O/ZnO hetero-nanobrush shows excellent improvement in both field emission and photocatalytic applications.Journal of Materials Chemistry 01/2012; 22(33-33):17055-17062. DOI:10.1039/C2jm32660d · 6.63 Impact Factor
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ABSTRACT: A novel visible-light-responding BiVO4–Cu2O–TiO2 ternary heterostructure composite was successfully fabricated via the preparation of BiVO4–TiO2 followed by coupling with Cu2O through facile wet chemistry methods based on the strategy of energy gap engineering. The as-fabricated composite was characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV–vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. Benefited from the rational design and construction, BiVO4–Cu2O–TiO2 exhibits a significantly enhanced photocatalytic activity for the degradation of rhodamine B (RhB) under the visible-light irradiation as compared with Cu2O and Cu2O–TiO2. Specifically, under the irradiation with an ordinary 9 W energy-saving fluorescent lamp for 8 h, the photocatalytic degradation ratio of RhB for 5 wt%BiVO4–40 wt%Cu2O–TiO2 reaches 97.8%. The enhanced photocatalytic activity of BiVO4–Cu2O–TiO2 can be ascribed to the matched band edge positions of BiVO4, Cu2O and TiO2, the heterojunction formations among them as well as the lower charge transfer resistance, favoring the separation of the photo-generated electron–hole pairs. A possible mechanism of the visible-light photocatalytic degradation of RhB is also proposed.Journal of Colloid and Interface Science 04/2015; 444. DOI:10.1016/j.jcis.2014.12.034 · 3.55 Impact Factor
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ABSTRACT: We have engineered the electronic structure at the interface between Cu2O and ZnO nanorods (NRs) array, through adjusting the carrier concentration of Cu2O. The electrodeposition of Cu2O at pH 11 acquired the highest carrier concentration, resulting in the largest interfacial electric field between Cu2O and ZnO, which finally led to the highest separation efficiency of photogenerated charge carriers. The optimized Cu2O/ZnO NRs array p-n heterostructures exhibited enhanced PEC performance, such as elevated photocurrent and photoconversion efficiency, as well as excellent sensing performance for the sensitive detection of glutathione (GSH) in PBS buffer even at applied bias of 0 V which made the device self-powered. Besides, the favorable selectivity, high reproducibility and extremely wide detection range, make such heterostructure a promising candidate for PEC biosensing applications, probably for the extended field of PEC water splitting or other solar photovoltaic beacons.Scientific Reports 01/2015; 5:7882. DOI:10.1038/srep07882 · 5.08 Impact Factor