Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• property modulations of the as-deposited and annealed films. The analyses show a reasonably good correlation with photoelectron spectroscopic measurements on the films and the bulk I–V characteristics acquired on a series of WOx/p-Si heterojunction diodes. The presence of a critical WOx thickness is

• fabricating WOx-based optoelectronic devices, including photovoltaic cells. Keywords: annealing; glancing angle sputter deposition; heterojunction; tungsten oxide; work function; Introduction Tungsten oxide (WOx; x ≤ 3) is a popular transition-metal oxide for various optoelectronic devices because of its

• , heterostructures having an n-type WOx layer on various p-type substrates such as p-Si [12][13], Cu2O [14], NiO [15], p-ZnO nanowires (NWs) [16], diamond [17], and BiVO4 [18], have a great technological importance in the field of heterojunction solar cells, LEDs, and resistance random access memory (RRAM) devices

CdSe/ZnS quantum dots as a booster in the active layer of distributed ternary organic photovoltaics

• Gabriela Lewińska,
• Piotr Jeleń,
• Zofia Kucia,
• Maciej Sitarz,
• Łukasz Walczak,
• Bartłomiej Szafraniak,
• Jerzy Sanetra and
• Konstanty W. Marszalek

Beilstein J. Nanotechnol. 2024, 15, 144–156, doi:10.3762/bjnano.15.14

• efficiencies is ternary organic cells [3][4][5][6]. The idea of ternary organic cells is to introduce additional material (donor or acceptor) into a typical donor–acceptor active layer in the bulk heterojunction (BHJ). This arrangement is supposed to combine the absorption of the three components to obtain

• in the millivolt region. The biggest change in performance concerned the short-circuit current. Conclusion Absorption spectra of the studied QDs indicate the role of a second acceptor (non-fullerene acceptor [62]) in the heterojunction volume. We may also consider QD materials as donors. By

Density functional theory study of Au-fcc/Ge and Au-hcp/Ge interfaces

• Olga Sikora,
• Małgorzata Sternik,
• Benedykt R. Jany,
• Franciszek Krok,
• Przemysław Piekarz and
• Andrzej M. Oleś

Beilstein J. Nanotechnol. 2023, 14, 1093–1105, doi:10.3762/bjnano.14.90

• of atomic layers and the epitaxial Au-fcc(001)/Ge(001) heterojunction shown in Figure 2 (two variants of mutual positions of the slabs are presented). This simplest heterostructure can be built by setting the [110] direction of the Au crystal parallel to the [100] direction of the Ge lattice [32

• tests performed to find the optimal thickness of the Au layer in the Au/Ge heterostructure with five Ge layers. The plot of the interfacial energy reveals a much weaker dependence on the number of Au layers. Values of the work of separation for the Au-fcc(001)/Ge(001) heterojunction include both the

• ) blocks as shown in Figure 1 (the supercell contains 96 Au and 72 Ge atoms). The Au lattice is extended in the Au-hcp[100] direction (with a mismatch of about 3%) and compressed in the Au-hcp[001] direction (mismatch of 6%). In this particular Au/Ge heterojunction, it is not possible to find a starting

Dual-heterodyne Kelvin probe force microscopy

• Benjamin Grévin,
• Fatima Husainy,
• Dmitry Aldakov and
• Cyril Aumaître

Beilstein J. Nanotechnol. 2023, 14, 1068–1084, doi:10.3762/bjnano.14.88

• reference substrate, a bulk organic photovoltaic heterojunction thin film, and an optoelectronic interface obtained by depositing caesium lead bromide perovskite nanosheets on a graphite surface. The conclusion provides perspectives for future improvements and applications. Keywords: heterodyne

• characterize the surface photovoltage dynamics are acquired on a photovoltaic organic bulk-heterojunction (BHJ) thin film. The time-constant values are shown to be fully consistent with the results of pump-probe KPFM. Last, the ability of DHe-KPFM to detect weak SPV signals is illustrated by investigating

A visible-light photodetector based on heterojunctions between CuO nanoparticles and ZnO nanorods

• Doan Nhat Giang,
• Nhat Minh Nguyen,
• Duc Anh Ngo,
• Thanh Trang Tran,
• Le Thai Duy,
• Cong Khanh Tran,
• Thi Thanh Van Tran,
• Phan Phuong Ha La and
• Vinh Quang Dang

Beilstein J. Nanotechnol. 2023, 14, 1018–1027, doi:10.3762/bjnano.14.84

• responsivity, photoconductive gain, detectivity, and sensitivity with maximum values of 1.38 A·W−1, 4.33, 2.58 × 1011 Jones, and 1934.5% at a bias of 2 V, respectively. The sensing mechanism of the p–n heterojunction of CuO/ZnO is also explored. Overall, this study indicates that the heterostructure of CuO

• nanoparticles and ZnO nanorods obtained via a simple and cost-effective synthesis process has great potential for optoelectronic applications. Keywords: CuO nanoparticles; heterojunction; optoelectronics; visible-light photodetector; ZnO nanorods; Introduction Optoelectronics is a field to accelerate the

• negatively charged ions [43][61], following Equation 5: In addition, decorating CuO NPs onto ZnO NRs forms p–n junctions between the two materials. The heterojunction formation leads to a concentration gradient of charge carriers at the interfaces. CuO NPs act as a p-type semiconductor, in which holes are

Cross-sectional Kelvin probe force microscopy on III–V epitaxial multilayer stacks: challenges and perspectives

• Mattia da Lisca,
• José Alvarez,
• James P. Connolly,
• Nicolas Vaissiere,
• Karim Mekhazni,
• Jean Decobert and
• Jean-Paul Kleider

Beilstein J. Nanotechnol. 2023, 14, 725–737, doi:10.3762/bjnano.14.59

• heterojunction stack can be explained by large surface defect densities in the highly doped n-InP and p-InP:Zn layers, with a much lower defect density in the InP:nid buffer layer. With further characterization and analysis, we have shown that white-light illumination reduces the surface band bending induced by

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• . Nanoarchitectonics of graphene nanoribbon heterojunctions has the potential to be a major technological breakthrough because of the rational design and by virtue of the extraordinary structural and electronic properties of such heterojunctions. However, graphene nanoribbon heterojunction structures made by bottom-up

• heterojunction interface (Figure 10) [126]. This synthesis strategy is based on the difference in dissociation energies of C–Br and C–I bonds. The growth order of the block copolymers of graphene nanoribbons can be controlled. Such heterojunctions provide a viable platform that can be used directly for

• improves single heterojunction yields. The improved structural control of heterojunctions is expected to enable the incorporation of graphene nanoribbon heterostructures with atomic precision in future nanoelectronic devices. Nanocarbons with a defined two-dimensional extent are also attractive targets for

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• light absorption, weaker charge separation, and poor charge carrier mobility. Researchers are concentrating on several strategies, such as doping, heterojunction formation, induction of the surface plasmon resonance effect, and the formation of Z-schemes, Schottky junctions, and engineered composites

• straddling gap heterojunction system is recognised as the standard heterojunction system where the band edges of one semiconductor are lower than those of the second semiconductor [119][156]. The conduction band position of semiconductor Y is highly negative relative to semiconductor X in type-II

• heterojunction systems. Conversely, the valence band potential of semiconductor X is highly positive. After being exposed to visible light, electrons from semiconductor Y's conduction band move to semiconductor X's conduction band while holes from semiconductor X's valance band move to semiconductor Y's valance

Photoelectrochemical water oxidation over TiO₂ nanotubes modified with MoS₂ and g-C₃N₄

• Phuong Hoang Nguyen,
• Thi Minh Cao,
• Tho Truong Nguyen,
• Hien Duy Tong and
• Viet Van Pham

Beilstein J. Nanotechnol. 2022, 13, 1541–1550, doi:10.3762/bjnano.13.127

• . The stability of the MoS2/TNAs heterojunction is higher than that of g-C3N4/TNAs. Keywords: band structure; g-C3N4/TiO2; MoS2/TiO2; photoelectrochemical; water splitting; Introduction Hydrogen energy has become a target pursued in the energy development strategies of many countries and regions

• ability. (i) TNAs only respond to ultraviolet (UV) light [22][23][24], and (ii) they exhibit fast carrier recombination [25]. Recently, the development of new heterojunction architectures through coupling TNAs with other semiconductor materials, especially low-bandgap semiconductors, led to a reduction of

• for 1 h and let it dry completely before the next test. We can conclude that the stability of the MoS2/TNAs heterojunction is higher than that of the g-C3N4/TNAs heterojunction. The decrease in catalytic activity of the PEC electrodes is explained by the leaching of the catalysts MoS2 and g-C3N4 after

LED-light-activated photocatalytic performance of metal-free carbon-modified hexagonal boron nitride towards degradation of methylene blue and phenol

• Nirmalendu S. Mishra and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2022, 13, 1380–1392, doi:10.3762/bjnano.13.114

• approaches to make it as a light-driven nanomaterial owing to its potential capabilities. The light-driven ability of HBN can be achieved through multiple strategies. These include varying the structural morphology, heterojunction formation with a suitable photocatalyst, and doping with heteroatoms. The

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

• Vishal Dutta,
• Ankush Chauhan,
• Ritesh Verma,
• C. Gopalkrishnan and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

• of Bi-based photocatalysts. Keywords: bismuth-based nanomaterials; environmental remediation; heterojunction formation; photocatalysis; Introduction Nanomaterials photocatalysis is a “green” integrative technique that combines physics, chemistry, and materials science with chemical engineering to

• , the catalyst should have a high CB position and a low VB position, resulting in a large bandgap. These two prerequisites are not compatible. As a direct consequence of this, heterojunctions are produced. To create heterojunction photocatalysts, two semiconductor photocatalysts are combined [44][45

• ]. Consequently, researchers focus their attention mainly on heterojunction photocatalysts. Promising Bi-based nanomaterials The overwhelming number of Bi-based semiconductors utilized in photocatalysis also have a distinctive layered structure and a bandgap of less than 3.0 eV. The connections between the layers

Rapid fabrication of MgO@g-C₃N₄ heterojunctions for photocatalytic nitric oxide removal

• Minh-Thuan Pham,
• Duyen P. H. Tran,
• Xuan-Thanh Bui and
• Sheng-Jie You

Beilstein J. Nanotechnol. 2022, 13, 1141–1154, doi:10.3762/bjnano.13.96

• heterojunction photocatalysts were synthesized by one-step pyrolysis of MgO and urea at 550 °C for two hours. The photocatalytic NO removal efficiency of the MgO@g-C3N4 heterojunctions was significantly improved and reached a maximum value of 75.4% under visible light irradiation. Differential reflectance

• conversion, DeNOx index, apparent quantum efficiency, trapping tests, and electron spin resonance measurements were carried out to understand the photocatalytic mechanism of the materials. The high reusability of the MgO@g-C3N4 heterojunction was shown by a five-cycle recycling test. This study provides a

• simple way to synthesize photocatalytic heterojunction materials with high reusability and the potential of heterojunction photocatalysts in the field of environmental remediation. Keywords: g-C3N4; MgO; nitric oxide; photocatalyst; visible light; Introduction The rapid development of industrialization

Spindle-like MIL101(Fe) decorated with Bi₂O₃ nanoparticles for enhanced degradation of chlortetracycline under visible-light irradiation

• Chen-chen Hao,
• Fang-yan Chen,
• Kun Bian,
• Yu-bin Tang and
• Wei-long Shi

Beilstein J. Nanotechnol. 2022, 13, 1038–1050, doi:10.3762/bjnano.13.91

• solvothermal method to obtain a novel 0D/3D heterojunction Bi2O3/MIL101(Fe) (BOM). The morphology and optical properties of the as-prepared Bi2O3/MIL101(Fe) composite were characterized. The photocatalytic activity of the synthesized samples was evaluated by degrading chlortetracycline (CTC) under visible

• Bi2O3 and MIL101(Fe), respectively. The enhanced photocatalytic activity is attributed to the formation of a Z-scheme heterojunction between Bi2O3 and MIL101(Fe), which is conducive to the rapid separation of photogenerated carriers and the enhancement of photogenerated electron and hole redox capacity

• –organic frameworks; MIL101(Fe); photocatalysts; Z-scheme heterojunction; Introduction Tetracyclines, as the second most widely used antibiotic in the world, have been widely applied in clinics, aquaculture, and livestock due to its broad-spectrum antibacterial properties and low price [1][2

Solar-light-driven LaFe_xNi_1−xO₃ perovskite oxides for photocatalytic Fenton-like reaction to degrade organic pollutants

• Chao-Wei Huang,
• Shu-Yu Hsu,
• Jun-Han Lin,
• Yun Jhou,
• Wei-Yu Chen,
• Kun-Yi Andrew Lin,
• Yu-Tang Lin and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 882–895, doi:10.3762/bjnano.13.79

• [24], carbon spheres [25], BiOBr [26], and Ag2CrO4 [27]) to form heterojunction structures or doping other atoms into LaFeO3 [28] are comprehensively developed. For instance, Orak et al. impregnated LaFeO3 or LaTi0.15Fe0.85O3 on the monolithic cordierite structure, which could provide light

Sodium doping in brookite TiO₂ enhances its photocatalytic activity

• Boxiang Zhuang,
• Honglong Shi,
• Honglei Zhang and
• Zeqian Zhang

Beilstein J. Nanotechnol. 2022, 13, 599–609, doi:10.3762/bjnano.13.52

• exceeded four times that of P25 under visible light irradiation [8]. The degradation of methyl orange by brookite nanoflowers was much more efficient than that by anatase nanorods [9]. Moreover, the heterojunction of brookite TiO2 can enhance the photocatalytic activity (e.g., the rutile/brookite TiO2

• heterojunction exhibited a synergetic effect, improving the photocatalytic activity for both hydrogen generation and organic dye degradation [10][11]). Similarly, the anatase/brookite heterojunction (38.2% brookite) also exhibited the highest degradation efficiency of cylindrospermopsin under UV–vis light [12

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

• . Numerous studies have demonstrated the enhancement of both near band edge (NBE) and defect emissions using ZnO decorated with metallic NPs [92][93]. The study in [92] showed a PL enhancement of the Au–ZnO heterojunction system by an order of magnitude when ZnO thin films were incorporated with gold

A chemiresistive sensor array based on polyaniline nanocomposites and machine learning classification

• Jiri Kroutil,
• Alexandr Laposa,
• Ali Ahmad,
• Jan Voves,
• Vojtech Povolny,
• Ladislav Klimsa,
• Marina Davydova and
• Miroslav Husak

Beilstein J. Nanotechnol. 2022, 13, 411–423, doi:10.3762/bjnano.13.34

• resistance due to the decrease of hole density within the p-type film [18]. In the case of the hybrid structures, a p–n heterojunction is formed between polyaniline and n-type nanostructures such as ZnO, WO3, In2O3, or fullerene [19]. The protons from polyaniline are transferred to the NH3 molecules. This

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• morphology. Recent studies have been focused on the modification of properties of SnO2 to increase the photocatalytic efficiency of SnO2, including bandgap engineering, defect regulation, surface engineering, heterojunction construction, and using co-catalysts, which will be thoroughly highlighted in this

• , surface engineering, heterojunction construction, co-catalyst, which will be thoroughly outlined in this review. Structure and bandgap SnO2 has a crystal structure similar to that of rutile TiO2 [41][42]. The unit cell parameters of rutile SnO2 are a = b = 0.47374 nm and c = 0.31864 nm [43]. In one unit

• Many attempts have been made to enhance the photocatalytic activity and take better advantage of SnO2 for the NOx abatement, including the combination with other metal oxides [70], organic semiconductors [71], or metallic nanomaterials [72] to form a heterojunction/composite photocatalyst, and self

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review

• Keshav Nagpal,
• Erwan Rauwel,
• Frédérique Ducroquet and
• Protima Rauwel

Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80

• terms of the Creative Commons Attribution 2.0 International License, https://creativecommons.org/licenses/by/2.0/). Figure 9b was adapted from [57], Z. Shi et al., “Localized Surface Plasmon Enhanced All-Inorganic Perovskite Quantum Dot Light-Emitting Diodes Based on Coaxial Core/Shell Heterojunction

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Monika Ozga,
• Katarzyna Gwozdz,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

• several articles reporting the photovoltaic effect for the n-type ZnO/p-type Si heterojunction [10][11][12][13][14]. In several works, open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and photovoltaic efficiency (Eff.) were reported for ZnO/Si solar cells. Such results were

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• to the test gas. The sensitivity of above ZnO-based self-powered sensor is 127.3% under 1000 ppm H2S. The piezoelectric output of sensor decreased with increase of the concentration of the tested gas, as shown in Figure 5e. In 2016, a self-powered gas sensor based on a NiO/ZnO heterojunction nanowire

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• ][91]. Researchers have also attempted to use heterojunctions as photocatalysts for PHP. For example, Wang et al. combined a pyrene-based polymer (P75) (Figure 10) with g-C3N4 to form a heterojunction [92]. The interface between P75 and g-C3N4 restrained charge recombination and promoted proton

• reduction. Peng et al. also prepared a photocatalyst with a surficial heterojunction composed of P76 (Figure 10) and g-C3N4 by facile rotary evaporation [93]. Using ascorbic acid as the sacrificial agent, the AQY of the heterojunction increased to 59.4% at 500 nm. It suggests that polymer/polymer

• heterojunctions could effectively improve the intermolecular charge transfer and suppress charge recombination. In addition, Tian et al. developed a series of polymer/polymer heterojunctions with CPs and g-C3N4 [94]. In particular, the heterojunction between benzotriazole–fluorene-based P77 (Figure 10) and g-C3N4

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• forms a p–n heterojunction, which improves the gas sensing abilities significantly [25]. Carbon-based materials are also promising gas sensors, because of their high surface area and high chemical and thermal stability [26][27]. Pristine graphene is a good conductor but rather inactive for gas sorption

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• because of its unique properties, such as ultrathin structure and heterojunction behavior [15]. In the search of other 2D materials, MXenes, which are a novel class of 2D metal carbides, were discovered at Drexel University in 2011 during research in which MAX phases were used as electrode materials in

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• synthesize AlGaN/AlN/GaN heterojunction NWs with controllable size. A single NW is transferred to a flexible poly(ethylene terephthalate) substrate and fixed by indium tin oxide electrodes to form an ohmic contact for the strain sensor. An external mechanical stress is introduced to study the performance of

• introduced during the epitaxial growth process [1][2][3]. Furthermore, the analysis of the internal polarization of the AlGaN/AlN/GaN heterojunction showed the existence of a 2D electron gas (2DEG), which effectively suppresses the degradation of the carrier mobility caused by the scattering at charge

• polarization distribution inside the heterojunction [7][8]. The piezotronic effect, described first by Zhong Lin Wang in 2007, is a combination of the piezoelectric effect and the properties of non-centrosymmetric semiconductor materials [9]. 1D semiconductor nanowires (NWs) are more suitable candidates for