Out-of-plane polarization induces a picosecond photoresponse in rhombohedral stacked bilayer WSe₂

• Guixian Liu,
• Yufan Wang,
• Zhoujuan Xu,
• Zhouxiaosong Zeng,
• Lanyu Huang,
• Cuihuan Ge and
• Xiao Wang

Beilstein J. Nanotechnol. 2024, 15, 1362–1368, doi:10.3762/bjnano.15.109

• intrinsic photoresponse time of approximately 3 ps. The ultrafast response time remains consistent across varying detection powers, demonstrating environmental stability and highlighting the potential in optoelectronic applications. Our study presents an effective strategy for enhancing the response time of

• photodetectors. Keywords: broken inversion symmetry; out-of-plane polarization; picosecond photoresponse; time-resolved photocurrent measurement (TRPC); WSe2; Introduction Two-dimensional (2D) van der Waals (vdW) ferroelectrics with dangling-bond-free surfaces exhibit ferroelectricity by effectively resisting

• research on internal carrier dynamics. Ultrafast photoresponse in the vertical graphene/3R WSe2/graphene heterojunction Theoretically, the OOP polarization in 3R WSe2 accelerates the separation of photogenerated carriers, suggesting that the vertical heterojunction may exhibit a fast photoresponse. We

Bolometric IR photoresponse based on a 3D micro-nano integrated CNT architecture

• Yasameen Al-Mafrachi,
• Sandeep Yadav,
• Sascha Preu,
• Jörg J. Schneider and
• Oktay Yilmazoglu

Beilstein J. Nanotechnol. 2024, 15, 1030–1040, doi:10.3762/bjnano.15.84

• height, resulting in a larger resistance change and responsivity increase. CNT architectures with initially low thermal coupling at atmospheric pressure can reduce the thermal coupling to the environment in vacuum, leading to a significant improvement in bolometric photoresponse [24]. The first design of

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

• bending can significantly modify (depending on the optical power) the tip–surface distance during the spectroscopic measurement (which has to be performed in open z-loop). Whenever possible, it is preferable to investigate the photoresponse of the sample under modulated or pulsed illumination. Provided

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

• and paves the way for developing more stable and effective visible-light photodetectors with remarkable photoresponse and shorter rise and decay times. Results and Discussion The morphologies of pure ZnO NRs and CuO NPs/ZnO NRs were examined via scanning electron microscopy (Figure 1). The field

• 0.7 μA, approximately the dark current, which shows the excellent recovery ability of the device. The time-dependent photoresponse at a constant bias of 2 V under 30 s illumination with 395 nm light at different intensities is presented in Figure 3b. When the light is turned on, the photocurrent

• sensitivity to other wavelengths including 464 nm (blue), 532 nm (green), and 640 nm (red). Figure 5a shows the room temperature I–V characteristics of the CuO NPs/ZnO NRs photodetector under different wavelengths. The photoresponse to wavelengths longer than 395 nm is in accordance with the UV–vis absorbance

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

• nanodots), dimension, and particle size of the photocatalyst. Functional properties such as bandgap, optoelectronic properties, surface area, photoresponse, and magnetic properties depend on particle size and morphology of Bi-based photocatalysts. For instance, the charge diffusion path can be decreased by

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

• . Specifically, reducing the bandgap of SnO2 will increase the photoresponse in the visible light region, making up 45% of the solar spectrum. Moreover, reducing the bandgap will also create many defect states that can decrease the recombination of photogenerated electron–hole pairs. There are many approaches to

A Au/CuNiCoS₄/p-Si photodiode: electrical and morphological characterization

• Adem Koçyiğit,
• Adem Sarılmaz,
• Teoman Öztürk,
• Faruk Ozel and
• Murat Yıldırım

Beilstein J. Nanotechnol. 2021, 12, 984–994, doi:10.3762/bjnano.12.74

• p-type Si by measuring I–V and C–V characteristics. The fabricated Au/CuNiCoS4/p-Si device exhibited good rectifying properties, high photoresponse activity, low series resistance, and high shunt resistance. The C–V characteristics revealed that capacitance and conductance of the photodiode are

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

• capability of diketopyrrolopyrrole (DPP) [59][60][61], Li and co-workers [62] combined DPP with triphenylamine and bipyridine groups to synthesize D–A polymers. A HER of 9.73 μmol·h−1 (3.5 mg) was achieved for P33 (Figure 4) due to the wide spectral range of the photoresponse. The apparent quantum yield (AQY

A self-powered, flexible ultra-thin Si/ZnO nanowire photodetector as full-spectrum optical sensor and pyroelectric nanogenerator

• Liang Chen,
• Jianqi Dong,
• Miao He and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1623–1630, doi:10.3762/bjnano.11.145

• -powered PDs yields full-spectrum (UV–visible–NIR) detection. The broad spectral photoresponse from UV to NIR is related to two different bandgap materials (wide bandgap = 3.2 eV and narrow bandgap = 1.1 eV). Remarkably, the photoresponse current is significantly enhanced by introducing the pyroelectric

• the range from UV to NIR. (a) Structure diagram of an ultra-thin (45 μm) p-Si/n-ZnO heterojunction device. (b) Optical image of the flexible PD. (c) Short-circuit photoresponse current of the ultra-thin (45 μm) p-Si/n-ZnO heterojunction device under zero bias by periodically turning on/off 325 nm UV

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• ][32]. A comparison of MSM photodetectors based on ZnMgO films prepared by spin coating and spray pyrolysis performed recently revealed that the sensitivity of the structures prepared by spin coating is higher as compared to those obtained by spray pyrolysis, while the photoresponse to UV irradiation

Structural optical and electrical properties of a transparent conductive ITO/Al–Ag/ITO multilayer contact

• Aliyu Kabiru Isiyaku,
• Ahmad Hadi Ali and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2020, 11, 695–702, doi:10.3762/bjnano.11.57

• enhances the photoresponse and the rectification properties of the ITO device. Single or double metal thin films of Ag, Al, Ti, Au, Cr, or Ni have been embedded between ITO layers [4][8][14][15][16][17]. Free electrons in the metal/ITO materials accelerate the separation of charge carriers and hence

Implementation of data-cube pump–probe KPFM on organic solar cells

• Benjamin Grévin,
• Olivier Bardagot and
• Renaud Demadrille

Beilstein J. Nanotechnol. 2020, 11, 323–337, doi:10.3762/bjnano.11.24

• single-point mode or over a 2D grid. The spectroscopic data are acquired in open z-loop configuration, which simplifies the pp-KPFM operation. The validity of the implementation is probed by measurements using electrical pumping. The dynamical photoresponse of a bulk heterojunction solar cell based on

• macroscopic electrical characterization (Figure S3 in Supporting Information File 1) remains however below the state-of-the-art for PTB7:PC71BM-based devices. We will describe later that an imperfect morphology may be the origin of the reduced performance. In a first step, the dynamic photoresponse of the

• successive spectroscopic curves. In this configuration, the cathode defines an equipotential level. In other words, the dynamic SP photoresponse is not position-dependent. Furthermore, here, the SPV can be directly compared to the open-circuit voltage deduced from the macroscopic electrical characterization

Fabrication and characterization of Si_1−xGe_x nanocrystals in as-grown and annealed structures: a comparative study

• Muhammad Taha Sultan,
• Adrian Valentin Maraloiu,
• Ionel Stavarache,
• Jón Tómas Gudmundsson,
• Andrei Manolescu,
• Valentin Serban Teodorescu,
• Magdalena Lidia Ciurea and
• Halldór Gudfinnur Svavarsson

Beilstein J. Nanotechnol. 2019, 10, 1873–1882, doi:10.3762/bjnano.10.182

• . A more than one order of magnitude higher intensity was obtained upon annealing at 900 °C (Figure 7c, right y-axis). In this context, it is worth mentioning that samples with SiGe deposited via dcMS alone resulted in amorphous structure [22], which did not show any measureable photoresponse. In

• above which the interface effect prevails and below which the photoresponse is associated with quantum confinement. That is, size and surface chemistry of the NCs and oxygen-related bonds are the factors determining the photocurrent spectra. It is well understood that annealing results in the formation

Construction of a 0D/1D composite based on Au nanoparticles/CuBi₂O₄ microrods for efficient visible-light-driven photocatalytic activity

• Weilong Shi,
• Mingyang Li,
• Hongji Ren,
• Feng Guo,
• Xiliu Huang,
• Yu Shi and
• Yubin Tang

Beilstein J. Nanotechnol. 2019, 10, 1360–1367, doi:10.3762/bjnano.10.134

• , enhancing photoresponse and providing more active sites. Our work shows a possible design of efficient photocatalysts for environmental remediation. Keywords: Au nanoparticles; 0D/1D composite; CuBi2O4 microrods; photocatalysis; photocatalytic degradation; Introduction Heterogeneous semiconductor

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

• RHE, and the operation of the photocathode. The value of the onset potential (Von), which is the condition attributed to a minimum charge transfer of the cell, was found to be just below that of the OER potential. All of the Co3O4 samples exhibited a photoresponse, suggesting photoabsorption and the

• utilization of photogenerated charges in the PEC cells. A strong thickness dependence on the photoresponse was found and showed that thicknesses of 100–170 nm are adequate to gain significant photocurrents. More interestingly, the 170 nm Co3O4 sample exhibited maximum photocurrent values in the applied

•  3a–c. The photoresponse of the Co3O4 samples in the potential range from −0.25 to 0.2 V vs RHE corresponds to the hydrogen evaluation reaction as shown in Figure 3a. The Co3O4 samples with thicknesses from 100 to 230 nm showed identical photocurrent values of ca. 1 mA·cm−2. An increased dark-current

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

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

• mV/s). A hysteresis-free cell was also constructed by combining the single-crystalline MABI with a P3HT HTL [85]. A layer of CsBi3I10 perovskite deposited by a conventional spin-coating/drying method on top of gold electrodes demonstrated a high photoresponse in the range of λ < 700 nm [169]. The

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

• therefore equal to the sum of a negative and a positive term, which will be referred to hereafter as “fast” and “slow” SPV components (SPVFast and SPVSlow, see Figure 2a) with regards to their different photoresponse dynamics. After switching the light off, the SP displays a fast positive shift followed by

• a slow stabilization towards its initial level. Remarkably, the tip height also displays a fast photoresponse, but shows almost no noticeable evolution under continuous illumination at this optical power. In other words, the maximum height photoresponse is quasi-instantaneous (at the time scale of

• our measurement) and does not scale with the illumination time. Consistent with the conclusions of the former work by Zhou et al. [16], this strongly supports the idea that the “fast” cantilever height photoresponse originates from an intrinsic photostriction effect (and not from a thermally induced

Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells

• Hana Krýsová,
• Josef Krýsa and
• Ladislav Kavan

Beilstein J. Nanotechnol. 2018, 9, 1135–1145, doi:10.3762/bjnano.9.105

• . Without post-calcination at 500 °C, the photocurrent density is negligible. The photoresponse was similarly negligible for the deposition temperature of 300 °C (data not shown). Only after calcination at 500 °C will the low-temperature-grown films become photoactive, where the photocurrent onset was

Non-equilibrium electron transport induced by terahertz radiation in the topological and trivial phases of Hg_1−xCd_xTe

• Alexandra V. Galeeva,
• Alexey I. Artamkin,
• Alexey S. Kazakov,
• Sergey N. Danilov,
• Sergey A. Dvoretskiy,
• Nikolay N. Mikhailov,
• Ludmila I. Ryabova and
• Dmitry R. Khokhlov

Beilstein J. Nanotechnol. 2018, 9, 1035–1039, doi:10.3762/bjnano.9.96

• . We show that both the positive photoresponse in films with x < 0.16 and the negative photoconductivity in samples with x > 0.16 have no low-energy threshold. The observed non-threshold positive photoconductivity is discussed in terms of a qualitative model that takes into account a 3D potential well

• . It was assumed that the negative photoresponse in the samples with the normal band structure is most likely related to the electron gas heating, while the positive photoconductivity in the zero band gap mercury cadmium telluride was reasonable to associate with interband transitions. In this work, we

• electron states in the barriers. This long-term photoconductivity is not discussed in this paper. It is important that the signs of the fast photoresponse for the normal and inverted band structure samples are opposite. For the latter, the photoconductivity is positive. Beside that, it demonstrates certain

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

• the photoresponse of the IL–TiO2 materials toward visible irradiation, thus photoactivity. The highest photoactivity was observed for samples prepared using a IL:TBOT molar ratio of 1:3, as observed for both ILs. From 59% to 61% of phenol used as a model compound was degraded after 60 min of

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

• the narrow bandgap of CdSe NRs serves to increase the photoresponse of CdSe/TiO2 composites until ≈725 nm. The CdSe (2 wt %)/TiO2 composite exhibits the highest photocatalytic activity for the degradation of rhodamine B in aqueous solution under simulated sunlight or visible light irradiation. The

Optical contrast and refractive index of natural van der Waals heterostructure nanosheets of franckeite

• Patricia Gant,
• Foad Ghasemi,
• David Maeso,
• Carmen Munuera,
• Elena López-Elvira,
• Riccardo Frisenda,
• David Pérez De Lara,
• Gabino Rubio-Bollinger,
• Mar Garcia-Hernandez and
• Andres Castellanos-Gomez

Beilstein J. Nanotechnol. 2017, 8, 2357–2362, doi:10.3762/bjnano.8.235

• of franckeite and fabricated electrochemical devices and field-effect devices [16]. Ray et al. have also recently measured the photoresponse of franckeite devices in the visible and near-infrared part of the spectrum [18]. These works showed that franckeite nanosheets have an attractively narrow

Light-induced magnetoresistance in solution-processed planar hybrid devices measured under ambient conditions

• Sreetama Banerjee,
• Daniel Bülz,
• Danny Reuter,
• Karla Hiller,
• Dietrich R. T. Zahn and
• Georgeta Salvan

Beilstein J. Nanotechnol. 2017, 8, 1502–1507, doi:10.3762/bjnano.8.150

• reported for other materials such as Alq3 [3]. The observed magnetoresistance effect was found to diminish approximately after two days of sample preparation in case of the HED-TIE devices kept under ambient conditions, while the photocurrent decreased from 120% to only 65%. The photoresponse time, however

Selective photodissociation of tailored molecular tags as a tool for quantum optics

• Ugur Sezer,
• Philipp Geyer,
• Moritz Kriegleder,
• Maxime Debiossac,
• Armin Shayeghi,
• Markus Arndt,
• Lukas Felix and
• Marcel Mayor

Beilstein J. Nanotechnol. 2017, 8, 325–333, doi:10.3762/bjnano.8.35

• beam [23][24]. It is also important to tailor the mass of the ejected fragment because one may later use the momentum transfer in this process to remove both fragments from an initially tightly collimated molecular beam. The photoresponse of the nitrobenzyl group has been studied in great detail in

• . We therefore analysed its photoresponse using UV absorption spectroscopy. Figure 3 displays the decay of the UV absorption of the trimer 1 in CH2Cl2 upon illumination by UV light at 254 nm and 365 nm respectively. The UV cuvette was exposed to a UV-lamp (8 W, 230 V, 50 Hz) at a constant distance of

• shifts and broadenings are common. Photoresponse of neutral model compounds in high vacuum Experiments with neutral molecules were done in a molecular beam machine as sketched in Figure 4. In order to generate a pulsed beam of isolated neutral molecules we used nanosecond pulsed laser desorption into a

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

• performance, high photoresponse gain, high responsivity (about 7 AW−1), fast response time (0.5 µs at 4 kHz) and great optoelectronic conversion efficiency of 900% in a wide operation bandwidth, from 450 to 1300 nm. The obtained photoresponse gain and the spectral width are attributed mainly to the high Ge

• test structure. The obtained photoresponse gain is attributed mainly to the Ge-nps packed into the SiO2 matrix and to the conditions during sample preparation, showing the direct connection between synthesis and opto-electrical properties of the nanostructures. The structures, investigated at room

• photodetector is 9 mm2. Characteristics recorded on structures containing Ge-nps in the SiO2 matrix, deposited at temperatures of 300, 400 and 500 °C, are presented in Figure 4. As one can see, they show a significant increase of the photoresponse as the temperature during the deposition increases. However, a