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

Changes of the absorption cross section of Si nanocrystals with temperature and distance

• Michael Greben,
• Petro Khoroshyy,
• Sebastian Gutsch,
• Daniel Hiller,
• Margit Zacharias and
• Jan Valenta

Beilstein J. Nanotechnol. 2017, 8, 2315–2323, doi:10.3762/bjnano.8.231

• parameters for spectroscopic studies and the design of Si NC optoelectronic devices, which is related to the strength of light absorption: the absorption cross section (ACS), σ. The ACS directly reflects the probability of optical transitions and is defined as the ratio [7] between photon absorption rate for

Hydrothermal synthesis of ZnO quantum dot/KNb₃O₈ nanosheet photocatalysts for reducing carbon dioxide to methanol

• Xiao Shao,
• Weiyue Xin and
• Xiaohong Yin

Beilstein J. Nanotechnol. 2017, 8, 2264–2270, doi:10.3762/bjnano.8.226

• displayed an absorption threshold at 376 nm. Compared with the pure KNb3O8 nanosheets, we found a significant red-shift of the absorption edge, which could attribute to the enhancement observed by the ZnO quantum dots upon visible-light absorption. The optical band gap (Eg) of semiconductors could be

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• multifunctional, sustainable photocatalytic material. The main drawback from which pure g-C3N4 suffers is poor light absorption and fast recombination of photogenerated electron–hole pairs, which leads to low photocatalytic efficiency and limits its applications [61]. To date, various attempts have been made to

• improve the light absorption of g-C3N4 and retard the recombination of photogenerated charge carriers to improve the photocatalytic efficiency. These strategies involve doping with metal atoms [70], non-metal doping [71], coupling with other carbon-based materials [72], and heterojunction formation by

• separation rate of photogenerated charge carriers to enhance the quantum yield. Notably, such heterojunction formation with semiconductors also enhances the light absorption efficiency of photocatalysts from UV to visible region of the solar energy spectrum. Furthermore, it is noteworthy to mention here that

Spin-chemistry concepts for spintronics scientists

• Konstantin L. Ivanov,
• Alexander Wagenpfahl,
• Carsten Deibel and
• Jörg Matysik

Beilstein J. Nanotechnol. 2017, 8, 1427–1445, doi:10.3762/bjnano.8.143

• of OSCs are shown in Figure 1. Ideally, singlet excitons in either donor or acceptor material are generated upon light absorption (a), here shown as S0→S1 transition. For sake of simplicity we just consider the absorption taking place in the donor: the singlet exciton can diffuse towards the

ZnO nanoparticles sensitized by CuInZn_xS_2+x quantum dots as highly efficient solar light driven photocatalysts

• Florian Donat,
• Serge Corbel,
• Halima Alem,
• Steve Pontvianne,
• Lavinia Balan,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 1080–1093, doi:10.3762/bjnano.8.110

• coupled to those of the QDs [10][11][12]. Heterostructured photocatalysts such as ZnO/CdS or TiO2/CdS or TiO2/PbS exhibit extended light absorption and improved photoreactivity due to the promoted separation of photo-induced charge carriers [13][14][15][16][17][18][19]. However, QDs such as CdS or PbS

• singlet oxygen and hydrogen peroxide play a key role in the degradation of the dye. The improved solar light photocatalytic activity of the ZnO/ZCIS composite is achieved by the increased lifetime of charge carrier transfer and by the increased light absorption in the visible region due to the

High photocatalytic activity of Fe₂O₃/TiO₂ nanocomposites prepared by photodeposition for degradation of 2,4-dichlorophenoxyacetic acid

• Shu Chin Lee,
• Hendrik O. Lintang and
• Leny Yuliati

Beilstein J. Nanotechnol. 2017, 8, 915–926, doi:10.3762/bjnano.8.93

• the charge transfer of O2−→Ti4+ and electron excitation from the valence band (VB) to the conduction band (CB) [7][20][21]. Both the heat treatment and addition of Fe species did not affect the light absorption of the TiO2 (NT) in the UV and visible region. Owing to the low loading of Fe, there was no

• photodeposition method were also measured (see Supporting Information File 1, Figure S4). Similar to the nanocomposites prepared by the impregnation method, the photodeposition treatment and addition of Fe species also did not much affect the light absorption or the Eg of both the TiO2 (PD_T) and Fe2O3/TiO2 (PD

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

Study of the surface properties of ZnO nanocolumns used for thin-film solar cells

• Neda Neykova,
• Jiri Stuchlik,
• Karel Hruska,
• Ales Poruba,
• Zdenek Remes and
• Ognen Pop-Georgievski

Beilstein J. Nanotechnol. 2017, 8, 446–451, doi:10.3762/bjnano.8.48

• region of silicon above approximately 650 nm, leading to efficiencies well above 13% at the cell level and above 12% at the module level [3][4]. However, the photo-generated current, determined by light absorption, is limited by the drift of generated electrons and holes across the absorber layer. Thus

Fabrication of black-gold coatings by glancing angle deposition with sputtering

• Alan Vitrey,
• Rafael Alvarez,
• Alberto Palmero,
• María Ujué González and
• José Miguel García-Martín

Beilstein J. Nanotechnol. 2017, 8, 434–439, doi:10.3762/bjnano.8.46

• 10.3762/bjnano.8.46 Abstract The fabrication of black-gold coatings using sputtering is reported here. Glancing angle deposition with a rotating substrate is needed to obtain vertical nanostructures. Enhanced light absorption is obtained in the samples prepared in the ballistic regime with high tilt

• angles. Under these conditions the diameter distribution of the nanostructures is centered at about 60 nm and the standard deviation is large enough to obtain black-metal behavior in the visible range. Keywords: black coatings; black metals; glancing angle deposition; light absorption; sputtering

• glancing angle deposition with substrate rotation. The coatings are made of columnar nanostructures that are produced due to shadowing effects in the ballistic regime of sputtering. In order to obtain enhanced light absorption in the visible range, high tilt angle is needed, which gives rise to a diameter

Photocatalysis applications of some hybrid polymeric composites incorporating TiO₂ nanoparticles and their combinations with SiO₂/Fe₂O₃

• Andreea Laura Chibac,
• Tinca Buruiana,
• Violeta Melinte and
• Emil C. Buruiana

Beilstein J. Nanotechnol. 2017, 8, 272–286, doi:10.3762/bjnano.8.30

• . The presence of Fe2O3 NPs extended the light absorption of TiO2 into the visible range, a feature that recommends their use in water purification under sunlight. Experimental Materials Titanium(IV) isopropoxide (TTIP), glacial acetic acid, tetraethyl orthosilicate (TEOS), iron(II) chloride

Grazing-incidence optical magnetic recording with super-resolution

• Gunther Scheunert,
• Sidney. R. Cohen,
• René Kullock,
• Ryan McCarron,
• Katya Rechev,
• Ifat Kaplan-Ashiri,
• Ora Bitton,
• Paul Dawson,
• Bert Hecht and
• Dan Oron

Beilstein J. Nanotechnol. 2017, 8, 28–37, doi:10.3762/bjnano.8.4

• by a factor of 10, which enables the use of low-power laser sources and pulses shorter than 20 ns, comparable to industry HAMR benchmarks [21]. Power requirements are further eased by using FePt recording media [24], designed for improved laser light absorption and lower operating temperatures

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• ]. As-prepared CdS NP have an absorption edge around 580 nm, which corresponds to a band gap value of about 2.12 eV in agreement with the value reported for CdS [23]. Bare GO also shows the excellent light absorption in the range of 200–800 nm. Various studies have confirmed that the band gap of GO

• GO affects the optical properties of the ternary nanocomposite and is responsible for the red shift in the absorption spectrum, which ultimately results in narrowing of the band gap, which not only enhances light absorption in the visible light region, but also facilities efficient mobility of the

Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

• Ionel Stavarache,
• Valentin Adrian Maraloiu,
• Petronela Prepelita and
• Gheorghe Iordache

Beilstein J. Nanotechnol. 2016, 7, 1492–1500, doi:10.3762/bjnano.7.142

• [12], the amorphous or crystalline state of the nanostructure [13], the shape of the nanostructure and whether or not it is layered [14]. Taking into account the influence of all these factors, the conduction or light absorption mechanism in the nanostructures appear to be quite complex, and it cannot