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

• procedure published by Liang et al. [28]. PTB7 (Ossila, Mw = 85 kDa, PDI = 2.0) and PC71BM (Solenne BV, 99% purity) were used as received. A thin layer of filtered (0.45 µm) PEDOT:PSS (Baytron A14083, Clevios) was spin-coated onto the activated ITO surface at 5000 rpm for 25 s, 4000 rpm for 60 s and 4000

• rpm for 1 s (≈30 nm) and annealed at 120 °C for 10 min under ambient conditions. The substrate was then transferred into an argon-filled glovebox for spin-coating of an active layer of the PTB7:PC71BM solution (1:1.5 weight ratio, 25 mg∙mL−1 total concentration) in anhydrous chlorobenzene. The blend

Anomalous current–voltage characteristics of SFIFS Josephson junctions with weak ferromagnetic interlayers

• Tairzhan Karabassov,
• Anastasia V. Guravova,
• Aleksei Yu. Kuzin,
• Elena A. Kazakova,
• Shiro Kawabata,
• Boris G. Lvov and
• Andrey S. Vasenko

Beilstein J. Nanotechnol. 2020, 11, 252–262, doi:10.3762/bjnano.11.19

• , e.g., single-flux quantum circuits [46][47], spintronic devices [48], memory elements [49][50][51][52][53][54][55][56][57][58] and spin-valves [59][60][61][62][63][64][65], magnetoelectronics [66][67][68], qubits [69], artificial neural networks [70], microrefrigerators [71][72], and low-temperature

• (G = cos θ) and anomalous (F = sin θ) Green’s functions and write the Usadel equations in the F layers in the form [94][95], where the positive and negative signs correspond to the spin-up (“↑”) and spin-down (“↓”) states, respectively. In terms of the electron fermionic operators ψ↑(↓) the spin-up

• state corresponds to the anomalous Green’s function F↑ ∼ ⟨ ψ↑ψ↓⟩, while spin-down state corresponds to F↓ ∼ ⟨ψ↓ψ↑⟩. The expressions ω = 2πT(n + 1/2) are the Matsubara frequencies, where n = 0, ±1, ±2, …, and h is the exchange field in the ferromagnet. The scattering times are labeled here as τz, τx, and

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• 2p3/2 and Co 2p1/2, respectively, indicating that the NiMoO4@Co3O4/CA composite electrode material contains both Co3+ and Co2+ [35]. The peaks at 787.1 and 802.8 eV with a spin-energy separation of 15.7 eV can be attributed to the shake-up satellite peaks of Co2+ [36]. Figure 4d shows the Ni 2p

• spectrum where two characteristic peaks appear at 856.5 and 874.3 eV along with two shake-up satellite peaks with a spin-energy separation of 17.8 eV, corresponding to the Ni 2p3/2 and the Ni 2p1/2 levels of Ni2+ [37][38]. The Mo 3d core-level spectrum (Figure 4e) shows two main peaks at 232.4 and 235.5 eV

Nonequilibrium Kondo effect in a graphene-coupled quantum dot in the presence of a magnetic field

• Levente Máthé and
• Ioan Grosu

Beilstein J. Nanotechnol. 2020, 11, 225–239, doi:10.3762/bjnano.11.17

• result of the interaction between a single magnetic impurity (e.g., a magnetic atom or a localized spin) and the free electrons in a nonmagnetic material (e.g., a continuum of states) [23][24]. The Kondo effect has been extensively studied theoretically within the framework of the EOM method applying the

• , to the right for spin-up electrons and to the left for spin-down electrons. Thus, the Kondo peaks originally located at the values of the chemical potentials are split into two new peaks. It was found that the differential conductance consists of an observable peak when the asymmetric bias voltage

• Hamiltonian, which describes the massless Dirac fermions in the left (L) and right (R) graphene leads and can be expressed as: where and cαskσ denote the creation and annihilation operators of the Dirac fermions with wave vector k and spin σ. Here, α identifies the channel in the left (L) and right (R

Recent progress in perovskite solar cells: the perovskite layer

• Xianfeng Dai,
• Ke Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2020, 11, 51–60, doi:10.3762/bjnano.11.5

• films Benefiting from the advances of various film deposition techniques, such as one-step spin coating [13][21], two-step sequential solution deposition [22][23] and inkjet printing fabrication [24][25], unprecedented progress in the improvement of the efficiency of PSCs has been made. To obtain high

• deposition approach based on one-step spin coating, which involves dripping a noncoordinate solvent such as toluene, chlorobenzene, dichlorobenzene or trifluorotoluene onto the perovskite film while spinning. This method has shown to produce extremely smooth and homogeneous perovskite films. PSCs with a PCE

• development of large-scale semi-transparent PSCs with large area, having diverse applications in the field of building-integrated photovoltaics (BIPVs) or as top cells for tandem devices. It has become a problem that a considerable amount of toxic Pb-containing material is discarded during the spin coating

Self-assembly of a terbium(III) 1D coordination polymer on mica

• Quentin Evrard,
• Giuseppe Cucinotta,
• Felix Houard,
• Guillaume Calvez,
• Yan Suffren,
• Carole Daiguebonne,
• Olivier Guillou,
• Andrea Caneschi,
• Matteo Mannini and
• Kevin Bernot

Beilstein J. Nanotechnol. 2019, 10, 2440–2448, doi:10.3762/bjnano.10.234

• spin carrier. However, a full saturation of the magnetization is not observed at 40 kOe, probably because of a partial loss of the magnetic anisotropy of TbIII in the deposits (vide infra). Dynamic magnetic measurements have also been performed (Figure 5). In these measurements, the magnetic

• susceptibility χ is measured as χ = χ′ + iχ″ where χ′ is the in-phase and χ″ is the out-of-phase magnetic susceptibility. Clear magnetic signals have been observed. This is a remarkable result for such a tiny amount of spin centers. The in-phase signal (χ′) has been used to estimate the weight of the deposits by

• layering on the mica substrate. This may be a result of i) the geometric distribution of the Tb coordination environment in the deposits similar to what has been observed when SMMs are dissolved in liquid matrixes [27] or ii) a modification of the spin–phonon coupling, as the phonon bath of such deposits

Semitransparent Sb₂S₃ thin film solar cells by ultrasonic spray pyrolysis for use in solar windows

• Jako S. Eensalu,
• Atanas Katerski,
• Erki Kärber,
• Lothar Weinhardt,
• Monika Blum,
• Clemens Heske,
• Wanli Yang,
• Ilona Oja Acik and
• Malle Krunks

Beilstein J. Nanotechnol. 2019, 10, 2396–2409, doi:10.3762/bjnano.10.230

• thin film when it is grown by CBD from an aqueous solution [18]. In 2018, PCE ≈ 5.7% was achieved for a cell based on a spin-coated Sb2S3 absorber, and the same group further increased the PCE of this cell to 6.4% by Zn doping during spin-coating of Sb2S3 [39][40]. Soon after, by doping Sb2S3 with CsOH

• , the PCE of planar Sb2S3 solar cells was boosted from 4.3% to 6.6% [41]. When looking forward to mass production on meter-sized substrates, however, spin-coating cannot be upscaled due to design limitations [42]. Industrialization is feasible only for low-cost, upscalable methods, to the detriment of

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• systems for quantum devices such as single-photon sources and spin–photon interfaces for quantum interconnects [1][2][3]. Points defects or color centers in SiC are considered as alternative candidates for quantum applications such as solid-state quantum bits [4][5], spin–photon interfaces [6], single

• -photon sources (SPSs) [7][8][9][10], nanoscale magnetic or electric fields sensors, and pressure or temperature sensors [3][11][12][13]. Electrically driven SPSs in SiC have been realized [14][15][16], and the coherent control of electron spin can be achieved up to 500 K [17]. SiC offers an alternative

• . Current studies aim to determine more accurately the quantum properties of these defects by using more recent methods of single-photon detection and single-color center isolation, and quantum coherent spin control. The parameters used to describe the quantum properties of color centers include zero-phonon

Polyvinylpyrrolidone as additive for perovskite solar cells with water and isopropanol as solvents

• Chen Du,
• Shuo Wang,
• Xu Miao,
• Wenhai Sun,
• Yu Zhu,
• Chengyan Wang and
• Ruixin Ma

Beilstein J. Nanotechnol. 2019, 10, 2374–2382, doi:10.3762/bjnano.10.228

• . Device fabrication Prior to spin-coating, the ITO glass substrate was cleaned sequentially with detergent, acetone, ethanol, deionized water, each for 15 min, then dried with a nitrogen flow, and then cleaned with UV/ozone for 20 min. A thin layer of SnO2 nanoparticles was spin-coated on the ITO

• substrate at 4000 rpm for 30 s and annealed at 150 °C for 10 min, then treated with UV/ozone for 20 min. The Pb(NO3)2 layer was prepared by spin-coating an aqueous Pb(NO3)2 solution (the concentration of Pb(NO3)2 was 1.0 M, doped with 0, 0.5, 1, 2, or 3 mg/mL PVP) at 4000 rpm for 20 s and annealed at 100 °C

• transport layer (HTL) was spin-coated on top of the CH3NH3PbI3 film using a Spiro-OMeTAD solution (the composition of the Spiro-OMeTAD solution was 72.3 mg Spiro-OMeTAD, 28.8 μL 4-tert-butylpyridine, 17.5 μL of lithium bis(trifluoromethanesulfonyl)imide solution (520 mg/mL in acetonitrile) and 1 mL

Atomic force acoustic microscopy reveals the influence of substrate stiffness and topography on cell behavior

• Yan Liu,
• Li Li,
• Xing Chen,
• Ying Wang,
• Meng-Nan Liu,
• Jin Yan,
• Liang Cao,
• Lu Wang and
• Zuo-Bin Wang

Beilstein J. Nanotechnol. 2019, 10, 2329–2337, doi:10.3762/bjnano.10.223

• with deionized water and dried in air. The SU-8 photoresist (2000.5, MicroChem) was spin-coated on the glass slides at a speed of 4000 rpm for 60 s. The slides were subsequently heated to 95 °C on a hot plate for 60 s to remove the solvent. The resulting SU-8 coating is approximately 400 nm thick

Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC₇₁BM-based organic photovoltaic cells

• Olivia Amargós-Reyes,
• José-Luis Maldonado,
• Omar Martínez-Alvarez,
• María-Elena Nicho,
• José Santos-Cruz,
• Juan Nicasio-Collazo,
• Irving Caballero-Quintana and
• Concepción Arenas-Arrocena

Beilstein J. Nanotechnol. 2019, 10, 2238–2250, doi:10.3762/bjnano.10.216

• thickness and morphology of the devices [32][35]. Spin-coating is one of the most widely used techniques for active layer deposition that provides a small active area film with a low root-mean-squared roughness of about 1–3 nm [36]. It has been proved that, with the incorporation of a third component in the

• at 80 °C for at least 12 h. Then, the ITO substrates were treated with UV-ozone plasma for 15 min. A PEDOT:PSS layer of ≈40 nm thickness was spin-coated on top of the ITO substrate at 4500 rpm for 1 min, and then it was thermally treated at 120 °C for 20 min. The active layers with and without FeS2

• were spin-coated onto ITO/PEDOT:PSS at 1900 rpm for 60 s at atmospheric conditions, and then the films were annealed at 80 °C for 15 min (active layer thickness ≈100 nm). A PFN layer (≈5–10 nm) was spin-coated at 6000 rpm on top of the active layer and exposed to thermal annealing for 15 min at 80 °C

Targeted therapeutic effect against the breast cancer cell line MCF-7 with a CuFe₂O₄/silica/cisplatin nanocomposite formulation

• B. Rabindran Jermy,
• Vijaya Ravinayagam,
• Widyan A. Alamoudi,
• Dana Almohazey,
• Hatim Dafalla,
• Lina Hussain Allehaibi,
• Abdulhadi Baykal,
• Muhammet S. Toprak and
• Thirunavukkarasu Somanathan

Beilstein J. Nanotechnol. 2019, 10, 2217–2228, doi:10.3762/bjnano.10.214

• inverse spinels occupying the A site, while Cu2+ prefers the B site. SQUID-vibrating sample magnetometry (VSM) analysis showed the formation of superparamagnetic behavior, while a temperature dependence study using field cooling and zero field cooling analysis (ZFC/FC) showed spin-glass-like surface

• nanometer-sized copper spinel clusters over HYPS (Figure 5). The particle size reduction tends to decrease the saturation magnetization. In particular, noncollinear spin arrangements present at the external nanoparticle surface play a major role, which in influences the response of the material to the

Ultrathin Ni_1−xCo_xS₂ nanoflakes as high energy density electrode materials for asymmetric supercapacitors

• Xiaoxiang Wang,
• Teng Wang,
• Rusen Zhou,
• Lijuan Fan,
• Shengli Zhang,
• Feng Yu,
• Tuquabo Tesfamichael,
• Liwei Su and
• Hongxia Wang

Beilstein J. Nanotechnol. 2019, 10, 2207–2216, doi:10.3762/bjnano.10.213

• ]. The Co 2p HRXPS spectrum (Figure 2c) shows characteristic peaks of Co 2p, which were both fitted with two main peaks at 781.4 eV and 796.7 eV, corresponding to a spin-energy separation of 15.3 eV. This energy can be attributed to the existence of Co3+ in the Ni1−xCoxS2 [32][33]. In the S 2p spectra

Liquid crystal tunable claddings for polymer integrated optical waveguides

• José M. Otón,
• Manuel Caño-García,
• Fernando Gordo,
• Eva Otón,
• Morten A. Geday and
• Xabier Quintana

Beilstein J. Nanotechnol. 2019, 10, 2163–2170, doi:10.3762/bjnano.10.209

• conditioned with spin-coated polyimide (PIA-2304, Lixon Aligner) for homogeneous LC alignment, parallel to the plate, along the waveguide. Both the glass surface and the waveguide were gently rubbed with a velvet cloth to induce the desired orientation. If an external electric field is applied to the LC

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

• methods, this review presents a survey of the latest advances in NV center nano-MRI. Keywords: nanodiamonds; nanoscale magnetic resonance imaging (nano-MRI); nitrogen-vacancy center; optically detected magnetic resonance; Review Introduction Spin echoes and free induction decays were first detected in

• (MRFM). Among the other approaches, magnetic dipole interaction is a new way to replace magnetic induction to allow for nanoscale MRI detection and has delivered promising results in the employment of spin sensors based on atomic-scale diamond impurities. The use of diamond NV centers with nano-MRI has

• allowed for in vivo imaging on the single-biomolecular scale at room temperature [12]. Other approaches not based on NV centers are evolving at the same pace as methods based on NV centers. For example, a new method for high-resolution nano-MRI coupling high spin sensitivity of nanowire-based MR detection

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• Instruments, USA). The pore size distribution was calculated using the Barret–Joyner–Halenda (BJH) method. The photoluminescence (PL) was measured on a fluorescence spectrophotometer (F-4500, Hitachi, Japan). Electron spin resonance (ESR) signals of the reactive species spin trapped by 5,5-dimethyl-1

Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions

• Da Shi,
• Justine Wallyn,
• Dinh-Vu Nguyen,
• Francis Perton,
• Delphine Felder-Flesch,
• Sylvie Bégin-Colin,
• Mounir Maaloum and
• Marie Pierre Krafft

Beilstein J. Nanotechnol. 2019, 10, 2103–2115, doi:10.3762/bjnano.10.205

• result is already obtained with C2F5, for which MBs of ≈1.0 μm in radius reach a half-life of ≈6.0 h. An atomic force microscopy investigation of spin-coated mixed films of DPPC/IONP@C2X5OEG8Den combinations (molar ratio 28:1) shows that the IONPs grafted with the fluorinated dendrons are located within

• indicate that fluorous interactions exist between F-hexane in the gas core and the fluorinated NPs and play a significant role for the MB size and stability characteristics. AFM analysis of spin-coated films of DPPC, dendronized iron oxide nanoparticles and their mixtures With the aim to understand if the

• dendronized IONPs are incorporated within the DPPC shell of the MBs or located at the surface of the shell (Figure 8), mixed films composed of phospholipid and nanoparticles were prepared by spin-coating on silicon wafers. The morphology of the films was investigated by AFM in the peak–force tapping mode. We

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

• expectedly showed no signals of Ti(III) around 3500 G due to its oxidation state Ti(IV), which is diamagnetic and thus EPR-silent. Both samples, C-P-ETS-10/60 and P-ETS-10/60, display a typical signal of high spin Fe(III) of dispersed paramagnetic centers. Their g-value of 4.3 is indicative of a large axial

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• –Ernzerhof (PBE) [20] pseudopotentials without spin–orbit interaction. Since the PBE functional fails to capture the electrical and optical properties of bulk MoO3 by a large margin (band gap of less than half of the experimental value), we also employ the Heyd–Scuseria–Ernzerhof (HSE06) hybrid functional

Magnetic properties of biofunctionalized iron oxide nanoparticles as magnetic resonance imaging contrast agents

• Natalia E. Gervits,
• Andrey A. Gippius,
• Alexey V. Tkachev,
• Evgeniy I. Demikhov,
• Sergey S. Starchikov,
• Igor S. Lyubutin,
• Alexander L. Vasiliev,
• Vladimir P. Chekhonin,
• Maxim A. Abakumov,
• Alevtina S. Semkina and
• Alexander G. Mazhuga

Beilstein J. Nanotechnol. 2019, 10, 1964–1972, doi:10.3762/bjnano.10.193

• . The contrast between the tissues in MRI images depends on their properties such as fat and water content as well as on the sequence of the procedure parameters. There are three main characteristics that determine the contrast of the image: 1) proton density; 2) the spin–lattice relaxation time T1; and

• 3) the spin–spin relaxation time T2. Generally, these natural differences in tissue properties provide the necessary contrast, but in some cases, the pathological focus cannot be visualized in the images, for instance, due to size effects or the difficulty in delineating boundaries to determine

• containing paramagnetic gadolinium, reduce the spin–lattice relaxation time (T1), which makes the pathological focus brighter. Negative contrast agents typically contain MNPs with Fe2+ and Fe3+ ions. They reduce the T2 relaxation time and therefore weaken the signal from the tissues that absorbed the agent

Oblique angle deposition of nickel thin films by high-power impulse magnetron sputtering

• Hamidreza Hajihoseini,
• Movaffaq Kateb,
• Snorri Þorgeir Ingvarsson and
• Jon Tomas Gudmundsson

Beilstein J. Nanotechnol. 2019, 10, 1914–1921, doi:10.3762/bjnano.10.186

• sputtering; magnetic anisotropy; nickel; Introduction The realization of electronics based on utilizing the electron spin degree of freedom, commonly referred to as spintronics, requires the integration of ferromagnetic films with semiconductors [1]. Nickel is a ferromagnetic heavy 3d transition metal that

Charge-transfer interactions between fullerenes and a mesoporous tetrathiafulvalene-based metal–organic framework

• Manuel Souto,
• Joaquín Calbo,
• Samuel Mañas-Valero,
• Aron Walsh and
• Guillermo Mínguez Espallargas

Beilstein J. Nanotechnol. 2019, 10, 1883–1893, doi:10.3762/bjnano.10.183

• , respectively). Theoretical calculations In order to get further insight into the donor–acceptor interactions between C60 and the TTF-based MOF, theoretical calculations were performed under the density functional theory (DFT). The MUV-2 framework was modelled as previously described [53], with a high-spin Fe

• a small bandgap calculated to be 0.90 eV in spin-up or α-channel, and 0.72 eV in spin-down or β-channel (Figure 6), slightly smaller than that predicted for pristine MUV-2 (0.86 eV in β-channel) [53]. Analysis of the projected density of states (PDoS) indicates that the valence band maximum (VBM) in

• calculations were performed under the density functional theory framework. Periodic boundary conditions (PBC) calculations were carried out with the FHI-AIMS (Version 171221) software [57]. MUV-2 was modelled as previously described, with Fe(III) ions in a high-spin d5-configuration. The guest C60 molecule was

Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films

• Corentin Guyot,
• Philippe Vandestrick,
• Ingrid Marenne,
• Olivier Deparis and
• Michel Voué

Beilstein J. Nanotechnol. 2019, 10, 1768–1777, doi:10.3762/bjnano.10.172

• values of Ψ and Δ are reported in Figure 10 as functions of the time. The behavior of the sample is complex during the first 10 min of annealing. During that period, the temperature rises from room temperature to 135 °C. We expect the mechanical constraints induced by the spin-coating to relax as soon as

• + cations was spin-coated using a Laurell WS-650-23B coater on RCA-cleaned Si(100) wafers fragments (2000 rpm, 90 s). Based on an average volume mass for PVA of 1.26 g/cm3, the 2% gold-to-PVA mass ratio corresponds to a volume fraction of fAu = 0.13% in the dry film. Optical scattering measurements Optical

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

• for the type-II Weyl semimetal [18] and quantum spin Hall insulator material [19]. Additionally, many other remarkable properties of WTe2 have also been revealed, such as the temperature-driven Lifshitz transition [20], pressure-induced superconductivity [21], linear Nernst response [22], etc

Precise local control of liquid crystal pretilt on polymer layers by focused ion beam nanopatterning

• Maxim V. Gorkunov,
• Irina V. Kasyanova,
• Vladimir V. Artemov,
• Alena V. Mamonova and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2019, 10, 1691–1697, doi:10.3762/bjnano.10.164

• display-quality glass substrates covered with ca. 150 nm thin transparent ITO electrodes. Polyimide (PI) is deposited onto the substrates by a conventional routine combining a precursor spin-coating and annealing at 190 °C for 1 h, which produces a mechanically robust PI layer of 10–20 nm thickness. Next

• of chromolane (spin-coated from 0.1 wt % ethanol solution and then dried at 95 °C). Note that in such a cell geometry, when the LC is vertically aligned at the top substrate, the difference between optical phase retardations of differently polarized normally incident light is fully determined by the