On the mechanism of piezoresistance in nanocrystalline graphite

• Sandeep Kumar,
• Simone Dehm and
• Ralph Krupke

Beilstein J. Nanotechnol. 2024, 15, 376–384, doi:10.3762/bjnano.15.34

• nanometers and, therefore, an excellent candidate for piezoresistance devices. Also, wafer-scale synthesis of NCG has already been achieved by Zhang et al. and modified by Riaz and co-workers [19][20]. Thickness-controlled growth of NCG was exploited to utilize it as an efficient broadband photodetector [21

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

• ideal candidate for UV photodetector applications [3]. Because of its octahedral lattice symmetry and partially filled d bands, WOx is also highly attractive as an electrochromic material for developing modern-day smart windows and display devices [4][5][6][7]. Exhibiting various stoichiometric and sub

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

• , have gained much attention from many research teams. This study describes a low-cost photodetector based on CuO nanoparticles and ZnO nanorods operating in a wide range of light wavelengths (395, 464, 532, and 640 nm). Particularly, under 395 nm excitation, the heterostructure device exhibits high

• 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

• properties of ZnO nanostructures, such as bandgap or conductivity [26]. Decorating ZnO with metals such as Ag, Au, Pd, Pt, and Al [27][28] can provide surface plasmonic effects that assist the electron transfer process in materials and extend the light absorption range of a photodetector [29][30]. However

Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• frequency. The AFM measurement was carried out in tapping mode. A 633 nm laser light aimed at the back side of the cantilever tip was reflected toward a position-sensitive photodetector, which provides feedback signals to piezoelectric scanners that maintain the cantilever tip at constant height (force

Direct measurement of surface photovoltage by AC bias Kelvin probe force microscopy

• Masato Miyazaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2022, 13, 712–720, doi:10.3762/bjnano.13.63

• was arranged in front of a photodetector of the OBD system to suppress the influence of the UV light on the deflection sensor. We used a commercial Ir-coated Si cantilever (NANOSENSORS, SD-T7L100) with a resonant frequency f0 of 913 kHz, a spring constant k of 650 N/m, and a quality factor Q of 7748

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

• the device. Furthermore, the CuNiCoS4 layer can also increase the current at zero bias voltage due its high absorption of the solar light. The CuNiCoS4 layer has a suitable bandgap value for the solar spectrum and can be used for optoelectronic applications, such as photodiode or photodetector, due to

• thermionic emission. Small differences of the ϕb and Rs values can be attributed to the used approximation [29]. The responsivity and specific detectivity are other important parameters of a photodiode or photodetector. While the responsivity represents the response to the incident light, the specific

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

• work, a new type of self-powered, high-performance ultra-thin p-Si/n-ZnO nanowire (NW) flexible photodetector (PD) and its application as full-spectrum optical sensor and pyroelectric nanogenerator (PENG) are demonstrated. The working mechanism of PDs for PENGs is carefully investigated and

• fabrication of the PENG utilizing a simple and low-cost method shows its potential applications in self-powered flexible electronic devices. Keywords: flexible; full-spectrum; photodetector; pyroelectric nanogenerator (PENG); self-powered; Introduction Full-spectrum photodetectors (PDs) that can detect

High-responsivity hybrid α-Ag₂S/Si photodetector prepared by pulsed laser ablation in liquid

• Raid A. Ismail,
• Hanan A. Rawdhan and
• Duha S. Ahmed

Beilstein J. Nanotechnol. 2020, 11, 1596–1607, doi:10.3762/bjnano.11.142

• monodisperse Ag2S NPs when using the CTAB surfactant. The optoelectronic properties of α-Ag2S/p-Si photodetector, such as current–voltage characteristics and responsivity in the dark and under illumination, were also improved after using the CTAB surfactant. The responsivity of the photodetector increases from

• 0.64 to 1.85 A/W at 510 nm after adding CTAB. The energy band diagram of the α-Ag2S/p-Si photodetector under illumination was constructed. The fabricated photodetectors exhibited reasonable stability after three weeks of storage under ambient conditions with a responsivity of 70% of the initial value

• . Keywords: cetyltrimethylammonium bromide (CTAB); laser ablation; monodisperse; photodetector; silver(I) sulfide (Ag2S); thiourea; Introduction Nanomaterials have attracted considerable attention due to their superior chemical and physical properties. The size-dependent properties of nanomaterials have

Antimicrobial metal-based nanoparticles: a review on their synthesis, types and antimicrobial action

• Matías Guerrero Correa,
• Fernanda B. Martínez,
• Cristian Patiño Vidal,
• Camilo Streitt,
• Juan Escrig and
• Carol Lopez de Dicastillo

Beilstein J. Nanotechnol. 2020, 11, 1450–1469, doi:10.3762/bjnano.11.129

• constituent can be determined after 24 h of incubation [149]. The cytofluorometry method is an advanced and important technique that allows for the accurate identification of a cell population with fluorescence tagging by using a flow cytometer and a photodetector [150]. In comparison to other techniques

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• ]. In this paper, for the first time, we study a new GNM-based photodetector using computational modeling. In order to do a complete device simulation, we initially perform ab initio DFT calculations to investigate the electronic and optical properties of the several materials used in devices channels

• , and then proceed with the design of the photodetector based on a suitable material. We further calculate the transport and photocurrent of the devices. To demonstrate improved performance of the proposed devices, we perform simulations on three types of devices. Graphene, GNMs and GNRs are materials

• that we employ as a device channel. Photodetector Structure Design Figure 1a–c shows structures of A4Z6-6, A4A4-6 and A4Z6-24 GNMs with their supercells indicated by quadrilaterals. In our notation, A and Z represent the edges of the GNM supercell along the armchair and zigzag directions of the

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• previously obtained through anodizing GaAs(100) wafers in alkaline KOH electrolyte. An IR photodetector based on the GaAs nanowires is demonstrated. Keywords: anodization; crystallographically oriented pores; gallium arsenide (GaAs); nanowires; neutral electrolyte; photocurrent; porous GaAs; Introduction

• number of tilted pores. One can conclude that etching in HNO3 electrolyte suppresses the nucleation of tilted pores as compared to anodization in HCl or H2SO4 electrolyte, resulting in the fabrication of non-porous GaAs nanowires, which are better suitable for photodetector applications. High-aspect

• these nanowires were tested for field emission, but not for photodetector applications. The nanowires were produced using electrochemical etching under optimized conditions in a mixed H3PO4/HCl electrolyte followed by chemical etching for reducing the diameter down to 150 nm. The authors of the work did

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

• of the alloy composition. Thin films were also prepared by aerosol spray pyrolysis deposition using the same sol–gel precursors for the purpose of comparison. The prepared films were tested for photodetector applications. Keywords: aerosol spray pyrolysis deposition; energy band tails; photodetector

• demonstrated on p-type Si [2][4] because p-type doping is still a big challenge to ZnO-based semiconductors. Liang et al. demonstrated a ZnMgO/p-Si heterojunction solar-blind UV photodetector with a BeO buffer layer [35]. In terms of the crystal structure of ZnMgO films used in photodetectors, three types of

• large band tails with both the incident and scattered photons in the Zn0.60Mg0.40O sample. The prepared ZnMgO thin films were tested for photodetector applications in the metal–semiconductor–metal (MSM) design configuration with coplanar metal Pd contacts in our previous paper [29]. The films

Size effects of graphene nanoplatelets on the properties of high-density polyethylene nanocomposites: morphological, thermal, electrical, and mechanical characterization

• Tuba Evgin,
• Alpaslan Turgut,
• Georges Hamaoui,
• Zdenko Spitalsky,
• Nicolas Horny,
• Matej Micusik,
• Mihai Chirtoc,
• Mehmet Sarikanat and
• Maria Omastova

Beilstein J. Nanotechnol. 2020, 11, 167–179, doi:10.3762/bjnano.11.14

• energy into heat were collected by a suitable optic (Au-coated mirrors, Edmund Optics) and focused on an IR photodetector (HgCdTe photoconductive detector, Kolmar Technologies, KMPV 11-1-J1/DC). Afterwards, a lock-in amplifier (Stanford Research Systems SR865) output the amplitude and phase of the

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• times relative electrical anisotropy. Subsequently, the photo-electrical conductance was studied to further explore the anisotropic photo-electric property. Our results revealed an anisotropic photo-electrical conductance with a maximum ratio of 4.33 among the 12 directions. Finally, a photodetector

• with twelve electrodes was used to distinguish the different wavelengths in the visible spectrum, demonstrating that 1T’-WTe2 shows promising application as an anisotropic photodetector. Results and Discussion Characterization of 1T’- WTe2 Figure 1a shows the typical orthorhombic crystalline structure

• great promise for future photodetector applications. Angle- and wavelength-dependent photodetector To evaluate the potential application of 1T’-WTe2 as a photoelectric sensor we also performed another angle-resolved photoelectric measurement. In this test, we first fixed the incident wavelength at 633

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• as an alternative to commercial photodetector devices with CdS and CdSe. Enhanced photoluminescence and photoelectrochemical properties of one-dimensional Lu2@C82 nanorods prepared through liquid–liquid interfacial precipitation between carbon disulfide and 2-propanol were demonstrated by Lu and co

Nanoscale spatial mapping of mechanical properties through dynamic atomic force microscopy

• Zahra Abooalizadeh,
• Leszek Josef Sudak and
• Philip Egberts

Beilstein J. Nanotechnol. 2019, 10, 1332–1347, doi:10.3762/bjnano.10.132

• follows: where A(m) is the calibrated amplitude signal in meters, A(v) is the measured amplitude signal in volts from the lock-in amplifier, and S is the sensitivity of the photodetector measured from the linear portion of a force versus distance curve. The force applied to the surface can be separated

Fe₃O₄ nanoparticles as a saturable absorber for giant chirped pulse generation

• Ji-Shu Liu,
• Xiao-Hui Li,
• Abdul Qyyum,
• Yi-Xuan Guo,
• Tong Chai,
• Hua Xu and
• Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

• of the output is connected to a 2 GHz photodetector (Thorlabs DET01CFC), and the detected signal is monitored by a 1 GHz real-time oscilloscope (Rigol DS6104). The 95.4% port is connected to an optical spectrum analyzer (Anritsu MS9710C) with a resolution of 0.05 nm. A radio frequency (RF) spectrum

Temperature-dependent Raman spectroscopy and sensor applications of PtSe₂ nanosheets synthesized by wet chemistry

• Mahendra S. Pawar and
• Dattatray J. Late

Beilstein J. Nanotechnol. 2019, 10, 467–474, doi:10.3762/bjnano.10.46

• well with the reported 2D transition metal dichalcogenides. A PtSe2 nanosheet-based sensor device was tested for its applicability as a humidity sensor and photodetector. The humidity sensor based on PtSe2 nanosheets showed an excellent recovery time of ≈5 s, indicating the great potential of PtSe2 for

• comparison of the temperature coefficient values corresponding to various 2D materials are shown in Table 2. The value of Δω for both Eg and A1g modes was found to be 6.11 cm−1 and 3.14 cm−1, respectively. Humidity sensor and photodetector based on few-layer PtSe2 nanosheets Figure 7a shows the typical

• . Figure 7d shows the I–t plot for the photodetector based on PtSe2 nanosheets with a response time of ≈110 s and a recovery time of ≈129 s. Conclusion In conclusion, we report on a wet chemistry method to grow PtSe2 nanosheets. The SEM and TEM analysis confirm the formation of PtSe2 nanosheets. Further

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• was controlled with a Linkam TMS 93 controller and a heating stage, THMSE 600. The intensity of light propagating through the cell under crossed polarizers, without the applied electric field, was registered with a photodetector, FLC Electronics PIN 20. The switching times were measured using the same

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

• favourable HER properties [20]. We also developed compact Co3O4 films by a reactive sputtering method, in which sputtered Co particles were converted into a compact Co3O4 film by controlling the flowing O2 gas, to offer a self-powered ultraviolet photodetector [17] and semitransparent photovoltaics [39]. It

Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation

• Nan Guan,
• Andrey Babichev,
• Martin Foldyna,
• Dmitry Denisov,
• François H. Julien and
• Maria Tchernycheva

Beilstein J. Nanotechnol. 2018, 9, 2248–2254, doi:10.3762/bjnano.9.209

• emitting diode (LED) and a nanowire photodetector connected with a waveguide is proposed. The light coupling efficiency from the LED to the detector is optimized as a function of the geometrical parameters of the system using the finite difference time domain simulation tool Lumerical. Starting from a

• between an LED and a photoconductive detector both based on GaN NWs [29]. The communication took place in free space. Using NWs located close to each other, the authors demonstrated a correlation between the LED on/off switching and the photodetector current variations. A waveguide for light channeling is

• combined all the basic building blocks of the optical circuit: emitter, coupling waveguide, and photodetector. However, the waveguide was not optimized. The platform used a multimode SiNx beam with a weak coupling to the active components. The reported coupling yield between the LED and the photodiode was

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

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

• photodetector is characterized by an on/off ratio as high as ≈105 and a prolonged stability retaining the unvaried response after a shelf-storage for at least three months (Figure 11a). The efficiency of solar cells based on Cs3Bi2I9 HP nanosheets was found to depend on the composition of the HTL layer. The

Artifacts in time-resolved Kelvin probe force microscopy

• Sascha Sadewasser,
• Nicoleta Nicoara and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2018, 9, 1272–1281, doi:10.3762/bjnano.9.119

• model system. In the experimental case, additional artifacts are observed due to constructive or destructive interference of the bias modulation with the cantilever oscillation. Also, in the case of light modulation, we demonstrate artifacts due to unwanted illumination of the photodetector of the beam

• cantilever eigenmodes, namely at 500 Hz and at 1428 Hz. We speculate that these deviations are due to possible capacitive cross talk between the ac voltage and the piezo cables or the photodetector. We can disregard these deviations since they are not related to the cantilever eigenmodes and have a different

• the flat CPD spectrum is again observed at the fundamental resonance frequency of the cantilever. This artifact can be explained by considering that part of the IM laser illumination reflects from the cantilever back side and the sample onto the position sensitive photodetector for the AFM detection

Surface characterization of nanoparticles using near-field light scattering

• Eunsoo Yoo,
• Yizhong Liu,
• Chukwuazam A. Nwasike,
• Sebastian R. Freeman,
• Brian C. DiPaolo,
• Bernardo Cordovez and
• Amber L. Doiron

Beilstein J. Nanotechnol. 2018, 9, 1228–1238, doi:10.3762/bjnano.9.114

• output edge where transmitted light is collected by a photodetector. Three polarization-maintaining optical fibers are supported by a silicon v-groove array and are optically aligned to the three waveguides permanently bonded to the chips. Each chip has two through-holes for fluidic access. Fluid lines