Optimization of Mo/Cr bilayer back contacts for thin-film solar cells

• Nima Khoshsirat,
• Fawad Ali,
• Vincent Tiing Tiong,
• Mojtaba Amjadipour,
• Hongxia Wang,
• Mahnaz Shafiei and
• Nunzio Motta

Beilstein J. Nanotechnol. 2018, 9, 2700–2707, doi:10.3762/bjnano.9.252

• is its optical reflectance. A back contact layer with high optical reflectance can contribute effectively to the light absorption by reflecting the non-absorbed photons back to the absorber layer. The optical reflectance of the the Mo/Cr bilayer was measured in the wavelength range of 200–1800 nm. As

Impact of the anodization time on the photocatalytic activity of TiO₂ nanotubes

• Jesús A. Díaz-Real,
• Geyla C. Dubed-Bandomo,
• Juan Galindo-de-la-Rosa,
• Luis G. Arriaga,
• Janet Ledesma-García and
• Nicolas Alonso-Vante

Beilstein J. Nanotechnol. 2018, 9, 2628–2643, doi:10.3762/bjnano.9.244

• generates charge carriers (electron–hole pairs) only under UV irradiation limiting the overall performance. This fact motivated the research on this material in order to increase the surface area and/or shift its light absorption toward the visible spectral region. Many reports are devoted to novel

• File 1), present an anodic (−0.08 V/Ag|AgCl) and a cathodic (−0.21 V/Ag|AgCl) peak associated to MB. These peaks become absent in the presence of light, supporting the idea of the oxidation of MB by holes. In the presence of MB, jph decreases due to its light absorption and a lower I0 reaches the

Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation

• Wei-Hung Hsu,
• Frances Camille P. Masim,
• Armandas Balčytis,
• Hsin-Hui Huang,
• Tetsu Yonezawa,
• Aleksandr A. Kuchmizhak,
• Saulius Juodkazis and
• Koji Hatanaka

Beilstein J. Nanotechnol. 2018, 9, 2609–2617, doi:10.3762/bjnano.9.242

• = 230 mJ/cm2. The above presented analysis takes into account the host material and the electron–ion plasma through the definition of permittivity, where the ENZ region defines the strongest light absorption. Due to the fast interaction, the permittivity conditions corresponding to the ENZ are changing

Thickness-dependent photoelectrochemical properties of a semitransparent Co₃O₄ photocathode

• Malkeshkumar Patel and
• Joondong Kim

Beilstein J. Nanotechnol. 2018, 9, 2432–2442, doi:10.3762/bjnano.9.228

• potential region of 0.2–0.4 V vs RHE as described below in detail. It is fundamental to optimise the thickness of the Co3O4 film. In order to improve light absorption, a thicker film is better. However, the Co3O4 film has a short carrier diffusion length due to the slow electron extraction kinetics

Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

• Valerio F. Gili,
• Lavinia Ghirardini,
• Davide Rocco,
• Giuseppe Marino,
• Ivan Favero,
• Iännis Roland,
• Giovanni Pellegrini,
• Lamberto Duò,
• Marco Finazzi,
• Luca Carletti,
• Andrea Locatelli,
• Aristide Lemaître,
• Dragomir Neshev,
• Costantino De Angelis,
• Giuseppe Leo and
• Michele Celebrano

Beilstein J. Nanotechnol. 2018, 9, 2306–2314, doi:10.3762/bjnano.9.215

• boost of the quality factors in these Mie resonators. This peculiar feature holds great potential to further enhance light–matter interaction. For this reason, these systems are currently the subject of intense investigations and strategies to attain light absorption enhancement [21], nonlinear

• pump wavelength. By engineering the geometrical parameters of dielectric nanoresonators working at the anapole mode, Wang and Dal Negro [21] demonstrated that light absorption can be enhanced. While this approach proved effective to finely tune the anapole condition, the pump light absorption and

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

Beilstein J. Nanotechnol. 2018, 9, 2209–2235, doi:10.3762/bjnano.9.207

Localized photodeposition of catalysts using nanophotonic resonances in silicon photocathodes

• Evgenia Kontoleta,
• Sven H. C. Askes,
• Lai-Hung Lai and
• Erik C. Garnett

Beilstein J. Nanotechnol. 2018, 9, 2097–2105, doi:10.3762/bjnano.9.198

• Evgenia Kontoleta Sven H. C. Askes Lai-Hung Lai Erik C. Garnett Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, Netherlands 10.3762/bjnano.9.198 Abstract Nanostructured semiconductors feature resonant optical modes that confine light absorption in specific areas called “hot

• light absorption and conversion to chemical energy take place. The photo-electrodes are in contact with an electrolyte that is the primary source of fuel together with the sunlight. In such a system, light absorption by the electrodes leads to the creation of electron–hole pairs, which after their

• on current density and often increases light absorption. This increased light absorption comes from optical resonances in nanomaterials, which have been studied extensively in both metallic (plasmonic) and dielectric material systems [9][10][11][12][13]. One hallmark of resonant absorption is the

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• can easily form nanostructures, such as nanoporous layers, nanowires or nanocolumns [5][11][12]. Because of its large band gap (3.2 eV [13]), light absorption is carried out by an organic or inorganic dye. The nanostructuration of the acceptor material is crucial for the cell performance [11], as it

• , its high hole mobility and its donor-like electronic properties [15]. Upon light absorption by the polymer, excitons are generated and they can be dissociated at the interface with TiO2, the polymer also acting as the hole-transporting layer. In this work, we investigated nanostructured TiO2 layers

• measurements on the TiO2/P3HT-COOH hybrid heterojunctions A 5 × 5 µm2 height image of a TiO2/P3HT-COOH HHJ is shown in Figure 6a. The corresponding current image in Figure 6b, obtained in short-circuit configuration upon illumination, shows values of photocurrent up to 25 pA. This confirms light absorption by

A visible-light-controlled platform for prolonged drug release based on Ag-doped TiO₂ nanotubes with a hydrophobic layer

• Caihong Liang,
• Jiang Wen and
• Xiaoming Liao

Beilstein J. Nanotechnol. 2018, 9, 1793–1801, doi:10.3762/bjnano.9.170

• enhanced by visible light. Characterization of light absorbance The absorbance spectra of TNTs, Ag-TNTs, Ag-Zn-TNTs and Ag-Zn-NDM-TNTs samples in the range of 300–800 nm are shown in Figure 6. The dark gray, orange, magenta and dark cyan lines correspond to the light absorption of the TNTs, Ag-TNTs, Zn-Ag

Controllable one-pot synthesis of uniform colloidal TiO₂ particles in a mixed solvent solution for photocatalysis

• Jong Tae Moon,
• Seung Ki Lee and
• Ji Bong Joo

Beilstein J. Nanotechnol. 2018, 9, 1715–1727, doi:10.3762/bjnano.9.163

• without charge recombination. Finally, each charge carrier can be consumed for surface redox reactions [9][15]. To achieve high performance in the overall photocatalysis system, the efficiency of each step should be improved [13]. Regarding the point of light absorption, the band gap energy range of the

• phase as well as a large surface area, should have beneficial effects including light absorption, charge separation and facile surface reaction, all resulting in the enhanced photocatalytic efficiency towards RhB degradation. As pointed out in the Introduction section and in our previous study, many

• on light absorption and charge separation by high anatase crystallinity with mixed phase composition as well as an additional large surface area, which would result in the enhanced photocatalytic efficiency towards RhB degradation. Conclusion We demonstrated the general synthesis of uniform TiO2

Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• be highly desirable to quantify the vertical extension of the space charge area at the origin of the spatial separation of the photocarrier and to check how it compares with the light absorption depth, and more importantly, with the photocarrier diffusion length. Regarding the photostrictive effect

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

• charge carriers, extension of the light absorption range and intensity, increase of the surface active sites, and higher photostability. Advantages and limitations for photoreduction of Cr(VI) over modified TiO2 are depicted in the Conclusion. The various challenges that restrict the technology from

• photocatalytic activity and light absorption range of TiO2 towards reduction of Cr(VI). The importance of the combination of metal oxides with TiO2 for photocatalytic reduction of Cr(VI) was discussed in section three. Section four highlights the enhancement of photocatalytic activity and the light absorption

• modified TiO2 photocatalysts The photocatalytic activity of a photocatalyst is characterized by its optical and electrochemical properties. Modifications of titania can hinder the recombination of charge carriers and extend the light absorption range, which are evident from optical and photoelectrochemical

Ag₂WO₄ nanorods decorated with AgI nanoparticles: Novel and efficient visible-light-driven photocatalysts for the degradation of water pollutants

• Shijie Li,
• Shiwei Hu,
• Wei Jiang,
• Yanping Liu,
• Yu Liu,
• Yingtang Zhou,
• Liuye Mo and
• Jianshe Liu

Beilstein J. Nanotechnol. 2018, 9, 1308–1316, doi:10.3762/bjnano.9.123

• (MO) and para-chlorophenol (4-CP). The high performance is attributed to the enhanced visible-light absorption properties and the promoted separation efficiency of charge carriers through the formation of the heterojunction between AgI and Ag2WO4. Additionally, AgI/Ag2WO4 exhibits durable stability

• Ag2WO4 has a clear absorption edge at about 400 nm [31], while AgI has a broader absorption band with the absorption edge located at around 460 nm [22]. For AgI/Ag2WO4 heterojunctions, a pronounced enhancement in visible-light absorption range is achieved when AgI content was progressively increased

• . This suggests that the introduction of AgI nanoparticles can optimize the light absorption capacity owing to the formation of a nanojunction between AgI and Ag2WO4. These facts indicate that AgI/Ag2WO4 heterojunctions can harvest more light and thus can be expected to be efficient VLD photocatalysts

Computational exploration of two-dimensional silicon diarsenide and germanium arsenide for photovoltaic applications

• Sri Kasi Matta,
• Chunmei Zhang,
• Yalong Jiao,
• Anthony O'Mullane and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1247–1253, doi:10.3762/bjnano.9.116

• suitable for photovoltaic applications, such as excellent visible light absorption, favorable exciton formation, and charge separation are equally essential for two-dimensional (2D) materials. Here, we systematically study 2D group IV–V compounds such as SiAs2 and GeAs2 with regard to their structural

• GW results, the BSE method was adopted to obtain the light absorption spectrum [21][22] and the optical band gap. BSE was solved by using the ten highest valance bands and ten lowest conduction bands and with a 13 × 5 × 1 k-grid. Using the band gaps obtained from GW and BSE functional methods the

• light absorption spectrum calculated from HSE functional in the visible light region (approx. 350–800 nm) compared with the AM1.5G solar spectrum. However, both materials exhibit an almost equal absorption in the wavelength region of 350–600 nm. Above this, GeAs2 still has good absorption up to around

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• , wettability, electrical and thermal conductivity, catalytic activity, light absorption and scattering resulting in enhanced performance over their bulk counterparts. A nanometer (nm) is an International System of Units (Système international d'unités, SI) unit that represents 10−9 meter in length. In

Optical orientation of nematic liquid crystal droplets via photoisomerization of an azodendrimer dopant

• Sergey A. Shvetsov,
• Alexander V. Emelyanenko,
• Natalia I. Boiko,
• Alexander S. Zolot'ko,
• Yan-Song Zhang,
• Jui-Hsiang Liu and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2018, 9, 870–879, doi:10.3762/bjnano.9.81

• trans and cis isomers are determined by the quantum yields (Φtrans and Φcis) and absorption coefficients and do not depend on exposure time and light intensity. In the case of an anisotropic solution, the light absorption depends on the direction of light propagation. In contrast to disordered cis

Synthesis and characterization of two new TiO₂-containing benzothiazole-based imine composites for organic device applications

• Anna Różycka,
• Agnieszka Iwan,
• Krzysztof Artur Bogdanowicz,
• Michal Filapek,
• Natalia Górska,
• Damian Pociecha,
• Marek Malinowski,
• Patryk Fryń,
• Agnieszka Hreniak,
• Jakub Rysz,
• Paweł Dąbczyński and
• Monika Marzec

Beilstein J. Nanotechnol. 2018, 9, 721–739, doi:10.3762/bjnano.9.67

• low current values on the order 10−7 mA. The reference device ITO/TiO2/P3HT/Au exhibited a higher value of current (≈0.02 mA). This behavior can be explained by inefficient light absorption of the active layer, a narrow range of maximum absorption bands (from 260 nm to 420 nm) and a high Eg (2.35 eV

Perovskite-structured CaTiO₃ coupled with g-C₃N₄ as a heterojunction photocatalyst for organic pollutant degradation

• Ashish Kumar,
• Christian Schuerings,
• Suneel Kumar,
• Ajay Kumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2018, 9, 671–685, doi:10.3762/bjnano.9.62

• a colorless, non-photosensitizing pollutant, bisphenol A (BPA). The superior photocatalytic performance of the CTCN heterojunction could be attributed to the appropriate band positions, close interfacial contact between the constituents and extended light absorption (both UV and visible region), all

• organic semiconductor with tri-s-triazine units, has drawn huge attention from researchers due to its excellent photocatalytic performance and unique properties such as appropriate band structure, visible light absorption and high chemical and thermal stability [2][4]. In addition, g-C3N4 consists of

• gap of g-C3N4 lies between 2.4–2.8 eV and therefore it has the capability to absorb visible light irradiation [23]. However, the photocatalytic efficiency of bare g-C3N4 is truncated by the high recombination rate of photogenerated charges (electrons and holes), insufficient light absorption and low

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• of nanoparticle formation and deposition using an sustainable approach is illustrated in Figure 6. Interaction of noble metals with semiconductor materials Most of the literature claims that the incorporation of plasmonic nanoparticles with semiconductors can extend light absorption towards the

• spatial charge separation of photoinduced carriers by creating an alternate permutation of band edges at the interface [146]. Some researchers found that both titanium nitride (TiN) and zirconium nitride (ZrN) displayed similar optical properties as Au and can replace Au NPs for vis–NIR light absorption

• geometry of the scales of a butterfly promote a light trapping effect from the UV to NIR range, which significantly increases the light absorption compared to a non-patterned system [149]. These works inspired the combination of bismuth vanadate (BiVO4) with the 3D architecture design of a butterfly wing

Fabrication and photoactivity of ionic liquid–TiO₂ structures for efficient visible-light-induced photocatalytic decomposition of organic pollutants in aqueous phase

• Anna Gołąbiewska,
• Marta Paszkiewicz-Gawron,
• Aleksandra Sadzińska,
• Wojciech Lisowski,
• Ewelina Grabowska,
• Adriana Zaleska-Medynska and
• Justyna Łuczak

Beilstein J. Nanotechnol. 2018, 9, 580–590, doi:10.3762/bjnano.9.54

• diffuse reflection (DR)/UV–vis spectra of the photocatalysts as well as for the pure ionic liquids used in this study are shown in Figure 4. The pristine TiO2 obtained by the solvothermal method showed the expected bandgap of 3.2 eV and very weak visible-light absorption. However, the visible-light

• tests of the IL–TiO2 composites for the phenol degradation under visible light irradiation (Table 1). Additionally, to understand why the obtained microparticles exhibited a strong light absorption over the visible range pure ILs were also examined as shown in Figure 4. The shape and nature of the

• absorption of the TiO2 photocatalysts appeared when the selected ionic liquids, [ODMIM][Cl] and [TDMIM][Cl], were applied in the TiO2 synthesis reaction. Moreover, with increasing IL:TBOT molar ratio, the optical absorption of the composites in the viible-light region was also greatly increased (compare for

Influence of the preparation method on the photocatalytic activity of Nd-modified TiO₂

• Patrycja Parnicka,
• Paweł Mazierski,
• Tomasz Grzyb,
• Wojciech Lisowski,
• Ewa Kowalska,
• Bunsho Ohtani,
• Adriana Zaleska-Medynska and
• Joanna Nadolna

Beilstein J. Nanotechnol. 2018, 9, 447–459, doi:10.3762/bjnano.9.43

• affected the light absorption of the photocatalysts. A redshift of the absorption edge toward the visible region was observed for the Nd-modified samples. The optical absorption edge was shifted further when the SHT method was applied. Nassuko et al. reported that the redshift can be ascribed to the new

• adsorption ability could be strongly related to the band-gap structure, which is affected by defects. With a reduced band gap or addition of sub-bands, TiO2 can respond to visible light, increasing its light absorption efficiency [48]. A schematic illustration showing impact of the preparation methods on the

Sugarcane juice derived carbon dot–graphitic carbon nitride composites for bisphenol A degradation under sunlight irradiation

• Lan Ching Sim,
• Jing Lin Wong,
• Chen Hong Hak,
• Jun Yan Tai,
• Kah Hon Leong and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2018, 9, 353–363, doi:10.3762/bjnano.9.35

• of g-C3N4. Hence, the charge separation efficiency should not be one of the main factors responsible for the enhancement of the photocatalytic activity of CD/g-C3N4. Instead, the light absorption capability was the dominant factor since the photoreactivity correlated well with the ultraviolet–visible

• [26][27], and degradation of pollutants [28][29][30]. However, the photocatalytic performance of bulk g-C3N4 remains unsatisfactory because of the fast recombination rate of electron pairs and narrower light absorption range over the entire solar spectrum. Turning g-C3N4 into a mesoporous nanorod

• degradation of indomethacin from the UV to NIR spectrum because of the superior electron transfer and extension of visible light absorption region after doping with N atoms [39]. Their group further enhanced the efficiency of CD/g-C3N4 through the incorporation of single-atom-dispersed silver. The optimum

CdSe nanorod/TiO₂ nanoparticle heterojunctions with enhanced solar- and visible-light photocatalytic activity

• Fakher Laatar,
• Hatem Moussa,
• Halima Alem,
• Lavinia Balan,
• Emilien Girot,
• Ghouti Medjahdi,
• Hatem Ezzaouia and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 2741–2752, doi:10.3762/bjnano.8.273

• recombination of photogenerated charge carriers (electrons and holes). To address these problems, a number of studies have been devoted to the improvement of light absorption and charge separation by hybridizing TiO2 with narrow bandgap semiconductors, doping with metal or nonmetal elements, association with

• the composite from 400 to ≈725 nm, which corresponds to the energy bandgap of CdSe NRs (≈1.61 eV) – a value slightly lower than the standard bandgap of CdSe (1.78 eV) [47]. This enhanced visible light absorption originates from the excitation of CdSe NRs and indicates a decrease of the bandgap with

• structure, the CdSe/TiO2 composites exhibit full visible and near-infrared light absorption and improved photocatalytic activity via charge separation between CdSe and TiO2 materials. The CdSe (2 wt %)/TiO2 composite was demonstrated to be the more efficient for the degradation of rhodamine B both under

Enhanced photoelectrochemical water splitting performance using morphology-controlled BiVO₄ with W doping

• Xin Zhao and
• Zhong Chen

Beilstein J. Nanotechnol. 2017, 8, 2640–2647, doi:10.3762/bjnano.8.264

• BiVO4 by simply tuning the solvent ratio in precursor solutions. Planar and porous W-doped BiVO4 thin films were prepared and compared. The porous film, which exhibits increased surface area and enhanced light absorption, has displayed enhanced charge separation and interfacial charge injection. Our

• quantitative analysis showed an enhancement of about 50% of the photoelectrochemical performance for the porous structure compared to the planar structure. This enhancement is attributed to improved light absorption (13% increase), charge separation (14% increase), and interfacial charge injection (20

• . By changing the solvent ratio, planar and porous nanostructured W-doped BiVO4 thin films were prepared. The photocurrent of the porous W-doped BiVO4 is ca. 50% higher than that of planar W-doped BiVO4. We have analyzed this improvement quantitatively with regard to contributions from light absorption

Au nanostructure fabrication by pulsed laser deposition in open air: Influence of the deposition geometry

• Rumen G. Nikov,
• Anna Og. Dikovska,
• Nikolay N. Nedyalkov,
• Georgi V. Avdeev and
• Petar A. Atanasov

Beilstein J. Nanotechnol. 2017, 8, 2438–2445, doi:10.3762/bjnano.8.242

• temperature and the subsequent increase in the resistance of the structures. The smooth surface and the high reflection coefficient of the Au film do not imply light absorption. It could be concluded that the modification of the electrical properties by light irradiation is a thermal effect. Unfortunately, an