| 1. |
- Alberto, Helena, V, et al.
(författare)
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Characterization of the Interfacial Defect Layer in Chalcopyrite Solar Cells by Depth-Resolved Muon Spin Spectroscopy
- 2022
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Ingår i: Advanced Materials Interfaces. - : John Wiley & Sons. - 2196-7350. ; 9:19
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Tidskriftsartikel (refereegranskat)abstract
- As devices become smaller and more complex, the interfaces between adjacent materials become increasingly important and are often critical to device performance. An important research goal is to improve the interface between the absorber and the window layer by inserting buffer layers to adjust the transition. Depth-resolved studies are key for a fundamental understanding of the interface. In the present experiment, the interface between the chalcopyrite Cu(In,Ga)Se-2 absorber and various buffer layers are investigated using low-energy muon spin rotation (mu SR) spectroscopy. Depth resolution in the nm range is achieved by implanting the muons with different energies so that they stop at different depths in the sample. Near the interface, a region about 50 nm wide is detected where the lattice is more distorted than further inside the absorber. The distortion is attributed to the long-range strain field caused by defects. These measurements allow a quantification of the corresponding passivation effect of the buffer layer. Bath-deposited cadmium sulfide provides the best defect passivation in the near interface region, in contrast to the dry-deposited oxides, which have a much smaller effect. The experiment demonstrates the great potential of low energy mu SR spectroscopy for microscopic interfacial studies of multilayer systems.
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| 2. |
- An, Rong, et al.
(författare)
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Friction of Ionic Liquid–Glycol Ether Mixtures at Titanium Interfaces : Negative Load Dependence
- 2018
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Ingår i: Advanced Materials Interfaces. - : John Wiley & Sons. - 2196-7350. ; 5:14
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Tidskriftsartikel (refereegranskat)abstract
- Structural reorientation of alkyl chains in the phosphonium cation of orthoborate ionic liquid mixed with glycol ether occurs with increasing normal load of the AFM tip. The flat reoriented structure, similar to the ‘blooming lotus leaf’, produces a new sliding interface that is responsible for the observed lower friction at higher loads. This work is reported by Rong An, Liangliang Huang, Faiz Ullah Shah and co‐workers in article number 1800263.
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| 3. |
- An, Rong, et al.
(författare)
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Friction of Ionic Liquid–Glycol Ether Mixtures at Titanium Interfaces : Negative Load Dependence
- 2018
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Ingår i: Advanced Materials Interfaces. - : John Wiley & Sons. - 2196-7350. ; 5:14
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Tidskriftsartikel (refereegranskat)abstract
- The atomic force microscopy experiments and nonequilibrium molecular dynamics (NEMD) simulations demonstrate a negative friction–load dependence to ionic liquid–glycol ether mixtures, that is, the friction decreases as the normal load increases. NEMD simulations reveal a structural reorientation of the studied ionic liquid (IL): as the normal load increases, the cation alkyl chains of ILs change the orientation to preferentially parallel to the tip scanning path. The flat‐oriented IL structures, similar to the “blooming lotus leaf,” produce a new sliding interface and reduce the friction. A further molecular dynamics simulation is carried out by adopting slit‐pore models to mimic the tip approaching process to confirm the dynamics of ILs. A faster diffusion of ILs in the smaller slit pore is observed. The faster diffusion of ILs in the more confined slit pore facilitates the structural reorientation of ILs. The resulted new sliding surface is responsible for the observed smaller friction at higher loads, also known as the negative friction–load dependence. These findings provide a fundamental explanation to the role of ILs in interfacial lubrications. They help to understand liquid flow properties under confinement, with implications for the development of better nanofluidic devices.
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| 4. |
- Anusuyadevi, Prasaanth Ravi, et al.
(författare)
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Synthetic Plant Cuticle Coating as a Biomimetic Moisture Barrier Membrane for Structurally Colored Cellulose Films
- 2023
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Ingår i: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Photonic films based on cellulose nanocrystals (CNCs) are sustainable candidates for sensors, structurally colored radiative cooling, and iridescent coatings. Such CNC-based films possess a helicoidal nanoarchitecture, which gives selective reflection with the polarization of the incident light. However, due to the hygroscopic nature of CNCs, the structural colored material changes and may be irreversibly damaged at high relative humidity. Thus, moisture protection is essential in such settings. In this work, hygroscopic CNC-based films are protected with a bioinspired synthetic plant cuticle; a strategy already adopted by real plants. The protective cuticle layers altered the reflected colors to some extent, but more importantly, they significantly reduced the water vapor permeance by more than two orders of magnitude, from 2.1 × 107 (pristine CNC/GLU film) to 12.3 × 104 g µm m−2 day−1 atm−1 (protected CNC/GLU film). This expands significantly the time window of operation for CNC/GLU films at high relative humidity.
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| 5. |
- Athle, Robin, et al.
(författare)
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Improved Endurance of Ferroelectric HfxZr1–xO2 Integrated on InAs Using Millisecond Annealing
- 2022
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Ingår i: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 9:27
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Tidskriftsartikel (refereegranskat)abstract
- Ferroelectric HfxZr1–xO2 (HZO) is typically achieved by crystallization of an amorphous thin film via rapid thermal processing (RTP) at time scales of seconds to minutes. For integration on III–V semiconductors, this approach can severely degrade the sensitive HZO/III–V interface. To evaluate whether a reduced thermal budget can improve the interface quality, millisecond duration thermal anneals are utilized using a flash lamp annealer (FLA) on HZO/InAs capacitors. Through thorough electrical characterization such as polarization hysteresis, endurance, and capacitance-voltage measurements, as well as synchrotron-based chemical interface characterization, the FLA and RTP treatments are compared and the FLA results are found in lower interface defect density and higher endurance, but also have generally lower remanent polarization (Pr) compared to RTP. Additionally, ways to achieve high Pr and low interface defect density using multiple lower energy flashes, as well as by pre-crystallization during the ALD growth step are investigated. Using FLA, Pr exceeding 20 µC cm−2 is achieved, with extended endurance properties compared to RTP treatment and a considerably decreased defect density, indicative of a higher quality HZO/InAs interface. This work presents valuable insight into the successful integration of ferroelectric HZO on low thermal budget III–V semiconductors.
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| 6. |
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| 7. |
- Bao, Qinye, et al.
(författare)
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Interfaces of (Ultra)thin Polymer Films in Organic Electronics
- 2019
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Ingår i: Advanced Materials Interfaces. - : WILEY. - 2196-7350. ; 6:1
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Forskningsöversikt (refereegranskat)abstract
- In this short review the energy level alignment of interfaces involving solution-processed conjugated polymer (and soluble small molecules) films is described. Some general material properties of conjugated polymers and their solution-processed films are introduced, and the basic physics involved in energy level alignment at their interfaces is then discussed. An overview of energy level bending in (ultra)thin conjugated polymer films (often referred to as "band bending") is given and the effects of ion-containing interlayers typically used in organic electronic devices such as polymer light emitting diodes and organic bulk heterojunction solar cells are explored. The review finishes by describing a few of the available computational models useful for predicting and/or modeling energy level alignment at interfaces of solution-processed polymer films and discusses their respective strengths and weaknesses.
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| 8. |
- Bao, Qinye, et al.
(författare)
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Regular Energetics at Conjugated Electrolyte/Electrode Modifier for Organic Electronics and Their Implications of Design Rules
- 2015
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Ingår i: Advanced Materials Interfaces. - : John Wiley & Sons. - 2196-7350. ; 2:12, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Regular energetics at a conjugated electrolyte/electrode modifier are found and controlled by equilibration of the Fermi level and an additional interface double dipole step induced by ionic functionality. Based on the results, design rules for conjugated electrolyte/electrode modifiers to achieve the smallest charge injection/exaction barrier and break through the current thickness limitation are proposed.
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| 9. |
- Benselfelt, Tobias, et al.
(författare)
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Explaining the Exceptional Wet Integrity of Transparent Cellulose Nanofibril Films in the Presence of Multivalent Ions-Suitable Substrates for Biointerfaces
- 2019
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Ingår i: Advanced Materials Interfaces. - : WILEY. - 2196-7350. ; 6:13
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Tidskriftsartikel (refereegranskat)abstract
- Cellulose nanofibrils (CNFs) assemble into water-resilient materials in the presence of multivalent counter-ions. The essential mechanisms behind these assemblies are ion-ion correlation and specific ion effects. A network model shows that the interfibril attraction indirectly influences the wet modulus by a fourth power relationship to the solidity of the network (E-w proportional to phi(4)). Ions that induce both ion-ion correlation and specific ion effects significantly reduce the swelling of the films, and due to the nonlinear relationship dramatically increase the wet modulus. Herein, this network model is used to explain the elastoplastic behavior of wet films of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized, carboxymethylated, and phosphorylated CNFs in the presence of different counter-ions. The main findings are that the aspect ratio of the CNFs influences the ductility of the assemblies, that the bivalency of phosphorylate ligands probably limits the formation of interfibril complexes with divalent ions, and that a higher charge density increases the friction between fibrils by increasing the short-range attraction from ion-ion correlation and specific ion effects. These findings can be used to rationally design CNF materials for a variety of applications where wet strength, ductility, and transparency are important, such as biomaterials or substrates for bioelectronics.
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| 10. |
- Biswas, Tuser, 1988-, et al.
(författare)
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Effective Pretreatment Routes of Polyethylene Terephthalate Fabric for Digital Inkjet Printing of Enzyme
- 2021
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Ingår i: Materials Science & Engineering. - : Wiley. - 0921-5107 .- 1873-4944.
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Tidskriftsartikel (refereegranskat)abstract
- Enzymes immobilized on synthetic polyethylene terephthalate (PET) textile surface by resource‐efficient inkjet printing technology can promote developments for various novel applications. Synthetic fabrics often require adequate pretreatments to facilitate such printing process. This work discusses PET–woven fabric pretreatment routes to improve wettability by alkaline, enzymatic, and plasma processes for effective printing of lysozyme using an industrial piezoelectric printhead. Results indicate that all pretreated samples contain a similar amount of enzymes upon printing. Plasma treated fabrics show relatively more hydrophilic surface characteristics, better protein binding stability, and lower retained activity. Alkali and cutinase‐treated samples possess relatively higher activity due to the greater amount of enzyme desorption to substrate solution. Depending on respective enzyme‐binding stability, a combination of a well-pretreated surface and inkjet as preferential placement technology, the approach of this study can be used as a facile enzyme immobilization method for suitable applications, for example, controlled‐release and bio‐sensing.
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