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

• 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

• estimated for the InP:Zn region, which is consistent with the fact that a negative SPV is expected for a p-type semiconductor because of surface band bending due to surface states produced by surface defects. In particular, the detection of a negative SPV implies that a downward band bending is present in

• ]. As illustrated in Figure 8, in the case of downward surface band bending in an p-type semiconductor, photogenerated holes are repelled from the surface, while photogenerated electrons flow in the direction of the surface, balancing the positive charges corresponding to empty donor-type surface states

• of 2 × 1012 eV−1·cm−2 was introduced. The energy reference is taken at the constant Fermi level, EF (blue line). The profile of the surface potential is also shown in orange (right y axis). Representation of the energy band profile in a p-type semiconductor under dark conditions and under

Humidity-dependent electrical performance of CuO nanowire networks studied by electrochemical impedance spectroscopy

• Jelena Kosmaca,
• Juris Katkevics,
• Jana Andzane,
• Raitis Sondors,
• Liga Jasulaneca,
• Raimonds Meija,
• Kiryl Niherysh,
• Yelyzaveta Rublova and
• Donats Erts

Beilstein J. Nanotechnol. 2023, 14, 683–691, doi:10.3762/bjnano.14.54

• chemisorption and physisorption at the nanowire interface, which suppress electronic transport inside the p-type semiconductor nanowire but enhance ionic transport in the water layers adsorbed on the nanowire surface. Possible physicochemical processes at the nanowire surface are discussed in line with

• ]. Copper oxide (CuO) nanowires are excellent candidates for applications in such devices owing to the inexpensive, simple and scalable bottom-up synthesis, and robust physical properties [7][8][9]. A high specific surface area of nanowires and a p-type semiconductor structure are suggested for highly

• , a decrease of conductivity in humid environments was observed, as expected for a p-type semiconductor material [6][13][18][19], other reports described a conductivity increase [20][21][22][23][24]. For example, arrays of free-standing nanowires showed an impedance increase upon exposure to humidity

High–low Kelvin probe force spectroscopy for measuring the interface state density

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

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• given by Similar results can be obtained for a p-type semiconductor. Next, we consider the charge Qit due to the interface states. In indirect-bandgap semiconductors such as Si with a low carrier density below 1017 cm−3, the charge (electron and hole) transfer between the interface and bulk states at

First-principles study of the structural, optoelectronic and thermophysical properties of the π-SnSe for thermoelectric applications

• Muhammad Atif Sattar,
• Najwa Al Bouzieh,
• Maamar Benkraouda and
• Noureddine Amrane

Beilstein J. Nanotechnol. 2021, 12, 1101–1114, doi:10.3762/bjnano.12.82

• indirect bandgap (1.41 eV), is a p-type semiconductor, and a possible alternative to orthorhombic α-SnSe for thermoelectric applications at room and high temperatures. The mechanical stability is confirmed for the α-SnSe alloy as all the calculated mechanical parameters show a linear increasing trend by

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

• high response to gas molecules at room temperature [30]. A disadvantage of rGO gas sensors is the long recovery time because of the high binding force between gas molecules and the graphene material [31]. rGO is a p-type semiconductor and can be used for gas sensing of low concentrations of NO2 at room

Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• detected phase sign indicates the majority carrier type and, hereby, enables the distinction between n-type and p-type semiconductor regions. In this way, SCM is applied to map the local carrier concentration and carrier type in semiconductor materials with a sensitivity between 1015 and 1020 atoms·cm−3

• , determined by our analytic procedure [32], as a function of VDC for both n- and p-type semiconductor materials. Using the complete metal–oxide–semiconductor equations, the Poisson–Boltzmann equation is solved for various active dopant concentration values ranging from 1015 to 1019 atoms·cm−3. In the sMIM

Preparation, characterization and photocatalytic performance of heterostructured CuO–ZnO-loaded composite nanofiber membranes

• Wei Fang,
• Liang Yu and
• Lan Xu

Beilstein J. Nanotechnol. 2020, 11, 631–650, doi:10.3762/bjnano.11.50

• semiconductor material to the other [7][8][9][10]. ZnO is a semiconductor material with a wide direct bandgap of 3.2 eV, which can absorb a small part of the solar spectrum in the UV region [11][12][13]. CuO is a nontoxic, chemically stable and naturally abundant material. It is a p-type semiconductor with a

Synthesis and acetone sensing properties of ZnFe₂O₄/rGO gas sensors

• Kaidi Wu,
• Yifan Luo,
• Ying Li and
• Chao Zhang

Beilstein J. Nanotechnol. 2019, 10, 2516–2526, doi:10.3762/bjnano.10.242

• Fermi energy levels equalize when two semiconducting systems are in contact via the transfer of carriers. Consequently, heterojunctions and regions of electron depletion will be formed at the interface between rGO, which is a p-type semiconductor, and ZnFe2O4, an n-type semiconductor. In addition, there

Prestress-loading effect on the current–voltage characteristics of a piezoelectric p–n junction together with the corresponding mechanical tuning laws

• Wanli Yang,
• Shuaiqi Fan,
• Yuxing Liang and
• Yuantai Hu

Beilstein J. Nanotechnol. 2019, 10, 1833–1843, doi:10.3762/bjnano.10.178

• can also be adjusted by applying strain or stress. Up to now, there is only a limited number of studies on tuning and controlling of non-equilibrium minority carriers (NEMC). Zhang et al. [14] studied the I–V characteristics of a p–n junction consisting of a p-type semiconductor without piezo-effect

Hydrophilicity and carbon chain length effects on the gas sensing properties of chemoresistive, self-assembled monolayer carbon nanotube sensors

• Juan Casanova-Cháfer,
• Carla Bittencourt and
• Eduard Llobet

Beilstein J. Nanotechnol. 2019, 10, 565–577, doi:10.3762/bjnano.10.58

• depending on whether metallic nanotubes are above or below the percolation threshold [29][30]. In contrast, multiwall CNT mats always present a mild p-type semiconductor behavior which improves device to device reproducibility without the added burden of sorting nanotubes according to their metallic or

Wet chemistry route for the decoration of carbon nanotubes with iron oxide nanoparticles for gas sensing

• Hussam M. Elnabawy,
• Juan Casanova-Chafer,
• Badawi Anis,
• Mostafa Fedawy,
• Mattia Scardamaglia,
• Carla Bittencourt,
• Ahmed S. G. Khalil,
• Eduard Llobet and
• Xavier Vilanova

Beilstein J. Nanotechnol. 2019, 10, 105–118, doi:10.3762/bjnano.10.10

• adsorption of NO2 on iron oxide nanoparticles, as previously reported for semiconductor metal oxide chemoresistors [35]. A deeper analysis of the sensor behavior reflected in Figure 7 and Figure 11 shows that both pristine and decorated CNT films behave as a p-type semiconductor. When nitrogen dioxide reacts

Graphene-enhanced metal oxide gas sensors at room temperature: a review

• Dongjin Sun,
• Yifan Luo,
• Marc Debliquy and
• Chao Zhang

Beilstein J. Nanotechnol. 2018, 9, 2832–2844, doi:10.3762/bjnano.9.264

• ]. The oxygen functional groups that locate on the surface of rGO lead to an electron transfer from rGO to oxygen functional groups, and holes become the main charge carriers, indicating that rGO acts as a p-type semiconductor [14][15][16]. Zhang et al. [17] prepared rGO room-temperature gas sensor with

• of semiconductor interfaces Reduced graphene oxide (rGO), which plays the role of a p-type semiconductor, can form heterojunctions when forming composites with most metal-oxide semiconductors. In the example of a SnO2–rGO sensor [45], SnO2 and rGO formed p–n heterojunctions. The enhancement mechanism

• . An interesting phenomenon found by the authors was that the pure ZnO sensor showed characteristics of a p-type semiconductor during the test. Two reasons were given for this. One was that a little carbon and nitrogen might be doped into ZnO due to the addition of graphite and nitrogen gas protection

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

• to the red end of the solar spectrum [162][163][164]. The p–n junction is formed by coupling a p-type (hole-rich) semiconductor with n-type (electron-rich) TiO2. As a result, the photoelectrons are diffused to the p-type semiconductor and holes are diffused to n-type TiO2 to create an inner electric

• have been reported on photocatalytic reduction of Cr(VI) by TiO2–p-type semiconductor metal oxide heterojunctions. The mechanism for visible-light-driven photocatalytic reduction of Cr(VI) on TiO2–p-type metal oxide heterojunctions is explained in Figure 9. Cuprous oxide (Cu2O) is a p-type

• simultaneous formation of molecular oxygen and hydroxyl radicals at the CoO surface [169]. NiO is a p-type semiconductor, which can conveniently be combined with different photocatalysts and the composite photocatalysts exhibit higher activity [170][171][172]. The introduction of nickel oxide into the TiO2

Facile synthesis of a ZnO–BiOI p–n nano-heterojunction with excellent visible-light photocatalytic activity

• Mengyuan Zhang,
• Jiaqian Qin,
• Pengfei Yu,
• Bing Zhang,
• Mingzhen Ma,
• Xinyu Zhang and
• Riping Liu

Beilstein J. Nanotechnol. 2018, 9, 789–800, doi:10.3762/bjnano.9.72

• . Recently, bismuth oxyhalides have been proposed as a new kind of narrow band gap p-type semiconductor photocatalyst material whose general formula is BiOX, where X represents Cl, Br or I. They crystallize in the tetragonal matlockite structure with space group P4/NMMS. In the crystal structure of all these

• obtained in XPS measurements are 0.96 and 2.27 eV, and the band gaps calculated from UV–vis spectra are 1.83 eV for BiOI and 3.16 eV for ZnO. Thus, the conduction band minimum energy should occur at –0.87 eV and –0.89 eV for BiOI and ZnO, respectively. While BiOI possesses a p-type semiconductor material

Anchoring of a dye precursor on NiO(001) studied by non-contact atomic force microscopy

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2018, 9, 242–249, doi:10.3762/bjnano.9.26

• (II) oxide (NiO); non-contact atomic force microscopy; p-type semiconductor; sub-molecular resolution; Introduction Inorganic substrates functionalized with organic molecules are nowadays highly regarded materials for emerging hybrid technologies including molecular electronics, photocatalysts or

Gas-sensing behaviour of ZnO/diamond nanostructures

• Marina Davydova,
• Alexandr Laposa,
• Jiri Smarhak,
• Alexander Kromka,
• Neda Neykova,
• Josef Nahlik,
• Jiri Kroutil,
• Jan Drahokoupil and
• Jan Voves

Beilstein J. Nanotechnol. 2018, 9, 22–29, doi:10.3762/bjnano.9.4

• oxides or noble metals [14][15][16][17]. Aside from n-type semiconductors, p-type semiconductor materials have also been extensively used for the detection of toxic gases [3][18][19]. Recently, nanocrystalline diamond (NCD) films have been utilized for advanced electronic devices because of their

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

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

• of 12.1% with excellent thermal stability [209]. Cuprous oxide (Cu2O) is a p-type semiconductor and is used for solar energy conversion, as sensors and for photocatalytic degradation. The controlled synthesis of Cu2O results in a vast palette of architectures including nanocubes, nanocages, nanowires

• –graphene hybrids, was used as a high-performance NO2 gas sensor (Figure 8). Copper oxide (CuO) is also a p-type semiconductor. CuO–graphene composites have also been used as anode material for LIBs [211][215]. Mathesh et al. prepared GO hybrid materials consisting of Cu ions complexed with GO, where Cu2

Role of oxygen in wetting of copper nanoparticles on silicon surfaces at elevated temperature

• Tapas Ghosh and
• Biswarup Satpati

Beilstein J. Nanotechnol. 2017, 8, 425–433, doi:10.3762/bjnano.8.45

• nanostructure fabrication have been carried out. CuO is a p-type semiconductor with a band gap of 1.4 eV [1][2]. Higher conductivity has been observed in CuO as compared to Cu2O, although higher carrier mobility has been observed in Cu2O [3]. However, the higher stability of CuO makes it more applicable. In the

Layered composites of PEDOT/PSS/nanoparticles and PEDOT/PSS/phthalocyanines as electron mediators for sensors and biosensors

• Celia García-Hernández,
• Cristina García-Cabezón,
• Fernando Martín-Pedrosa,
• José Antonio De Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2016, 7, 1948–1959, doi:10.3762/bjnano.7.186

• EMs, three different materials with different characteristics and electrocatalytic activity towards phenols were tested, including gold nanoparticles (AuNPs), a copper phthalocyanine (CuPc) (a p-type semiconductor) and a lutetium bisphthalocyanine (LuPc2) (a sandwich-type derivative with free radical

Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• been formed between PANI and In2O3 nanofibers, in which PANI is a p-type semiconductor and In2O3 nanofibers presents as an n-type semiconductor [21][27][34]. The changes of the depletion layer of the p–n heterojuction are shown in Figure 10. The width of the depletion section is related to the doping

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• barriers in the conduction and valence band. Furthermore, there are no influences of interface states taken into account that might give rise to additional space charges and barriers. If we consider a narrow band gap, p-type semiconductor 1, and a wide gap, n-type semiconductor 2, the J–V characteristics

Highly NO₂ sensitive caesium doped graphene oxide conductometric sensors

• Carlo Piloto,
• Marco Notarianni,
• Mahnaz Shafiei,
• Elena Taran,
• Dilini Galpaya,
• Cheng Yan and
• Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 1073–1081, doi:10.3762/bjnano.5.120

• . Both responses are approximately linear and proportional to the gas concentration. Since NO2 is an oxidative gas with strong electron-withdrawing ability, the decrease in resistance confirms the p-type semiconductor behaviour of the sensors, like the one observed for carbon nanotubes [64]. For GO-Cs

Integration of ZnO and CuO nanowires into a thermoelectric module

• Dario Zappa,
• Simone Dalola,
• Guido Faglia,
• Elisabetta Comini,
• Matteo Ferroni,
• Caterina Soldano,
• Vittorio Ferrari and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2014, 5, 927–936, doi:10.3762/bjnano.5.106

• at 30 min [23]. Copper oxide is a p-type semiconductor with a narrow band-gap of 1.2 eV with monoclinic crystal structure [38]. In the present work, copper oxide nanowires have been grown by thermal oxidation of metallic Cu thin-film layer, previously deposited by RF sputtering on 20 mm × 20 mm