Anion passivation effect on metal-oxide nano-architecture offers a highly controllable platform for improving charge selectivity and extraction, with direct relevance to their implementation in hybrid solar cells. In current work, we demonstrated the incorporation of fluorine (F) as an anion dopant to address the defect-rich nature of ZnO nanorods (ZNR) and improve the feasibility of its role as electron acceptor. The detailed morphology evolution and defect engineering on ZNR were studied as a function of F-doping concentration (x). Specifically, the rod-shaped arrays of ZnO were transformed into taper-shaped arrays at high x. A hypsochromic shift was observed in optical energy band gap due to the Burstein-Moss effect. A substantial suppression on intrinsic defects in ZnO lattice directly epitomized the novel role of fluorine as an oxygen defect quencher. The results show that 10-FZNR/P3HT device exhibited two-fold higher power conversion efficiency than the pristine ZNR/P3HT device, primarily due to the reduced Schottky defects and charge transfer barrier. Essentially, the reported findings yielded insights on the functions of fluorine on (i) surface –OH passivation, (ii) oxygen vacancies (Vo) occupation and (iii) lattice oxygen substitution, thereby enhancing the photo-physical processes, carrier mobility and concentration of FZNR based device.

Monochromated low-loss EELS ͑electron energy-loss spectroscopy͒ is explored as an analytical technique for nanoscale mapping of the electronic band gap energy on arsenic-implanted ZnO, CdZnO, and InGaN compounds. Its accuracy is confirmed independently with Raman spectroscopy. From a ternary compound, the relationship between the band gap energy and the chemical composition is determined, a powerful application of low-loss EELS. The effects of electron beam delocalization are discussed using examples from In 0.25 Ga 0.75 N quantum wells.

The crystallographic plane of the ZnO nanocrystals photocatalyst is considered as a key parameter for an effective photocatalysis, photoelectrochemical reaction and photosensitivity. In this paper, we report a simple method for the synthesis of a new (101) high-energy plane bounded ZnO nanocubes photocatalyst directly on the FTO surface, using a seed-mediated ultrasonic assisted hydrolysis process. In the typical procedure, high-density nanocubes and quasi-nanocubes can be grown on the substrate surface from a solution containing equimolar (0.04 M) zinc nitrate hydrate and hexamine. ZnO nanocubes, with average edge-length of ca. 50 nm, can be obtained on the surface in as quickly as 10 min. The heterogeneous photocatalytic property of the sample has been examined in the photodegradation of methyl orange (MO) by UV light irradiation. It was found that the ZnO nanocubes exhibit excellent catalytic and photocatalytic properties and demonstrate the photodegradation efficiency as high as 5.7 percent/μg mW. This is 200 times higher than those reported results using a relatively low-powered polychromatic UV light source (4 mW). The mechanism of ZnO nanocube formation using the present approach is discussed. The new-synthesized ZnO nanocubes with a unique (101) basal plane also find potential application in photoelectrochemical devices and sensing.

Fibrous, ultra small nanorod-constructed Pt nanocubes (PtNCs) directly grown on the substrate surface show enhanced heterogeneous catalytic reduction of methyl orange with efficiency 10 3 times higher compared to those in homogeneous reaction. The PtNCs may find potential application in organic reactions and photoelectrochemical devices.

A simple low-temperature solution processed bismuth-doped ZnO nanorods (NRs) and poly­(3-hexylthiophene) (P3HT) were used as electron acceptor and donor, respectively, in a hybrid inorganic–organic photovoltaic system. Controlling Bi precursor concentration via solution processing (hydrothermal method) plays an important role in altering the morphology, structure, and intrinsic defects of ZnO NRs. Interstitial doping of Bi–Bi2O3 into ZnO (BiZO) NRs results in simultaneous improvement of the open circuit voltage and short circuit current density primarily due to prolonged charge carrier recombination lifetime, increased donor–acceptor interfacial areas with efficient exciton dissociation, and charge carrier mobility. As a result, the power conversion efficiency of the 2 wt % BiZO NRs-P3HT device was significantly enhanced by 55% compared with that of the pristine device. Overall, our study highlighted the immense potential of BiZO NRs as an excellent electron acceptor for fabrication of hybrid optoelectronic devices.

In this article, a simple new technique has been developed for the preparation of ZnO/ZnAl₂O₄-mixed metal oxide (MMO) as anode materials for visible light dye-sensitized (DS) photodetector using Zn/Al-layered double hydroxide (LDH) as precursor. Subsequently, a detailed correlation between the structural properties of the prepared samples and the photoresponsive behavior of the fabricated DS photodetectors was elucidated. Specifically, it is evidenced that a high surface area of the prepared mesoporous MMO anode materials exhibit excellent dye absorptivity and thus facilitate free electron transfer and increase the photocurrent in the fabricated DS photodetector. A significant bathochromic shift was observed in the optical energy of the prepared MMO samples under the increment of molar ratio, providing a short electron transfer pathway in the optimized Z7A DS photodetector, which in turn demonstrated photo-responsivity and photo-detectivity of 6 mA/W and 1.7 × 10⁺¹⁰Jones, respectively. This work presents an alternative approach for the design of an eco-friendly MMO-based DS photodetector.

This Research Article reports an unusually high efficiency heterogeneous photodegradation of methyl orange (MO) in the presence of Ag nanoparticle-loaded ZnO quasi-nanotube or nanoreactor (A-ZNRs) nanocatalyst grown on FTO substrate. In typical process, photodegradation efficiency of as high as 21.6% per μg per Watts of used catalyst and UV power can be normally obtained within only a 60-min reaction time from this system, which is 10(3) order higher than the reported results. This is equivalent to the turnover frequency of 360 mol mol(-1) h(-1). High-density hexagonal A-ZNRs catalysts were grown directly on FTO substrate via a seed-mediated microwave-assisted hydrolysis growth process utilizing Ag nanoparticle of approximately 3 nm in size as nanoseed and mixture aqueous solution of Zn(NO3)·6H2O, hexamethylenetetramine (HMT), and AgNO3 as the growth solution. A-ZNRs adopts hexagonal cross-section morphology with the inner surface of the reactor characterized by a rough and rugged structure. Transmission electron microscopy imaging shows the Ag nanoparticle grows interstitially in the ZnO nanoreactor structure. The high photocatalytic property of the A-ZNRs is associated with the highly active of inner side's surface of A-ZNRs and the oxidizing effect of Ag nanoparticle. The growth mechanism as well as the mechanism of the enhanced-photocatalytic performance of the A-ZNRs will be discussed.

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