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Self-assembled growth of blue-green-yellow-red InGaN quantum dots (QDs) on GaN templates using plasma-assisted molecular beam epitaxy were investigated. We concluded that growth conditions, including small N2 flow and high growth temperature are beneficial to the formation of InGaN QDs and improve the crystal quality. The lower In/Ga flux ratio and lower growth temperature are favorable for the formation of QDs of long emission wavelength. Moreover, the nitrogen modulation epitaxy method can extend the wavelength of QDs from green to red. As a result, visible light emissions from 460 nm to 622 nm have been achieved. Furthermore, a 505 nm green light-emitting diode (LED) based on InGaN/GaN MQDs was prepared. The LED has a low external quantum efficiency of 0.14% and shows an efficiency droop with increasing injection current. However, electroluminescence spectra exhibited a strong wavelength stability, with a negligible shift of less than 1.0 nm as injection current density increased from 8 A/cm2 to 160 A/cm2, owing to the screening of polarization-related electric field in QDs.

MnSi ~1.7 nanowires (NWs) with a single orientation and a large aspect ratio have been formed on a Si(110) surface with the molecular beam epitaxy method by a delicate control of growth parameters, such as temperature, deposition rate, and deposition time. Scanning tunneling microscopy (STM) was employed to study the influence of these parameters on the growth of NWs. The supply of free Si atoms per unit time during the silicide reaction plays a critical role in the growth kinetics of the NWs. High growth temperature and low deposition rate are favorable for the formation of NWs with a large aspect ratio. The orientation relationship between the NWs and the reconstruction rows of the Si(110) surface suggests that the NWs grow along the 1 1 ¯ 0 direction of the silicon substrate. High-resolution STM and backscattered electron scanning electron microscopy images indicate that the NWs are composed of MnSi ~1.7 .

We report on the growth and characterization of lateral InAs/GaAs (001) quantum-dot molecules (QDMs) suitable for single QDM optical spectroscopy. The QDMs, forming by depositing InAs on GaAs surfaces with self-assembled nanoholes, are aligned along the [\"Equation missing\" ] direction. The relative number of isolated single quantum dots (QDs) is substantially reduced by performing the growth on GaAs surfaces containing stepped mounds. Surface morphology and X-ray measurements suggest that the strain produced by InGaAs-filled nanoholes superimposed to the strain relaxation at the step edges are responsible for the improved QDM properties. QDMs are Ga-richer compared to single QDs, consistent with strain- enhanced intermixing. The high optical quality of single QDMs is probed by micro-photoluminescence spectroscopy in samples with QDM densities lower than 10 8 cm −2 .

In addition to oxidative stress and impaired angiogenesis, the overexpression of metalloproteinases (MMPs) and proinflammatory cytokines, which are promoted by hyperglycemia, causes chronic inflammation in diabetic wounds. Herein, TA‐siRNA nanogels are prepared for the first time on the basis of the self‐assembling interaction between tannic acid (TA) and short interfering RNA (siRNA). The efficient, biodegradable nanogels are cross‐linked with poly(vinyl alcohol) (PVA), human‐like collagen (HLC), TA, and borax to prepare adaptive, conductive PHTB (TA‐siRNA) hydrogels. In response to high levels of reactive oxygen species (ROS), the ROS‐responsive borate ester bonds in the hydrogels are oxidized and broken, and TA‐siRNA nanogels are released into cells to reduce the expression of the MMP‐9. Moreover, the TA and HLC promote collagen expression, reduce inflammation, and ROS level. It is found that electrical stimulation (ES) promotes the in vivo release of TA‐siRNA nanogels from PHTB (TA‐siRNA) hydrogels and endocytosis of the nanogels. The combination therapy using ES and PHTB (TA‐siRNA) hydrogels accelerates the healing of diabetic wounds by reducing the levels of ROS and MMP‐9 and promoting the polarization of macrophages, production of collagen, and angiogenesis. This study provides insights on the design of functional gene‐delivery and efficient therapeutic strategies to promote the repair of diabetic chronic wounds. The efficient, nontoxic, biodegradable self‐assembled tannic acid‐short interfering RNA (TA‐siRNA) nanogels could promote the effective cellular internalization of siRNA to reduce the expression of the target gene. Adaptive conductive hydrogels combined with electrical stimulation (ES) could promote the repair of diabetic chronic wounds by scavenging reactive oxygen species (ROS), metalloproteinases‐9 (MMP‐9), and proinflammatory factors and promoting macrophage polarization and vascularization.

Self-assembled monolayers (SAMs) have displayed unpredictable potential in efficient perovskite solar cells (PSCs). Yet most of SAMs are largely suitable for pure Pb-based devices, precisely developing promising hole-selective contacts (HSCs) for Sn-based PSCs and exploring the underlying general mechanism are fundamentally desired. Here, based on the prototypical donor-acceptor SAM MPA-BT-BA (BT), oligoether side chains with different length (i.e., methoxy, 2-methoxyethoxy, 2-(2-methoxyethoxy)ethoxy group) were custom-introduced on the benzothiadiazole unit to produce the target SAMs with acronyms MPA-MBT-BA (MBT), MPA-EBT-BA (EBT), and MPA-MEBT-BA (MEBT), respectively, and acting as HSCs for efficient Sn-Pb PSCs and all-perovskite tandems. The introduction of oligoether side chains enables HSCs effectively accelerate hole extraction, regulate the crystal growth and passivate surface defects of Sn-Pb perovskites. In particular, benefiting from the enhanced Sn-Pb perovskite film quality and the suppressed interfacial non-radiative recombination losses, EBT-tailored LBG devices yield a champion efficiency of 23.54%, enabling 28.61% efficient monolithic all-perovskite tandems with an impressive V OC of 2.155 V and excellent operational stability as well as 28.22%-efficiency 4-T tandems. The development of hole-selective contacts for Sn-based perovskite solar cells is highly desirable. Here, the authors report self-assembled monolayers with oligoether side chains on the benzothiadiazole unit and achieve an efficiency of 28.61% for operationally stable all-perovskite tandems.

Equilibrium geometries and properties of self-assembled (InN)12n (n = 1–9) nanoclusters (nanowires and nanosheets) are studied using the GGA-PBE (general gradient approximation with Perdew–Burke–Ernzerh) method. The relative stabilities and growth patterns of semiconductor (InN)12n nanoclusters are investigated. The odd-numbered nano-size (InN)12n (n is odd) have weaker stabilities compared with the neighboring even-numbered (InN)12n (n is even) ones. The most stable (InN)48 nanosheet is selected as a building unit for self-assembled nano-size film materials. In particular, the energy gaps of InN nanoclusters show an even–odd oscillation and reflect that (InN)12n (n = 1–9) nanoclusters are good optoelectronic materials and nanodevices due to their energy gaps in the visible region. Interestingly, the calculated energy gaps for (InN)12n nanowires varies slightly compared with that of individual (InN)12 units. Additionally, the predicted natural atomic populations of In atoms in (InN)12n nanoclusters show that the stabilities of (InN)12n nanoclusters is enhanced through the ionic bonding and covalent bonding of (InN)12n (n = 1–9) nanoclusters.

This study investigates the effects of solvent type, ODPA concentration, and solution temperature on the growth, surface coverage, and structural order of n-octadecylphosphonic acid (ODPA) self-assembled monolayers (SAMs) on zinc oxide (ZnO) surfaces. We explore the impacts of isopropanol and ethanol as solvents, considering their differing dielectric constants and lower toxicity compared to non-polar alternatives like toluene. The results indicate that ODPA SAMs formed more rapidly in isopropanol, with a growth rate of 0.7% per minute, compared to 0.2% per minute in ethanol. However, ethanol resulted in slightly higher surface coverage (97%) than isopropanol (96%). Moreover, increasing the ODPA concentration from 0.03 to 0.14 mM enhanced surface coverage; however, further increases in concentration did not lead to a corresponding increase in SAM coverage due to molecular interactions. The solution temperature also significantly influenced the growth rate of the SAM, with temperatures rising from 30 to 60 °C enhancing growth. However, higher temperatures (above 60 °C) affected the SAM structure, leading to defects in the monolayer. This study provides a comprehensive understanding of how solvent type, concentration, and solution temperature influence SAM formation, offering valuable insights for optimizing deposition conditions to enhance device performance in optoelectronic applications.

The growing socioeconomic burden of musculoskeletal injuries and limitations of current therapies have motivated tissue engineering approaches to generate functional tissues to aid in defect healing. A readily implantable scaffold‐free system comprised of human bone marrow‐derived mesenchymal stem cells embedded with bioactive microparticles capable of controlled delivery of transforming growth factor‐beta 1 (TGF‐β1) and bone morphogenetic protein‐2 (BMP‐2) was engineered to guide endochondral bone formation. The microparticles were formulated to release TGF‐β1 early to induce cartilage formation and BMP‐2 in a more sustained manner to promote remodeling into bone. Cell constructs containing microparticles, empty or loaded with one or both growth factors, were implanted into rat critical‐sized calvarial defects. Micro‐computed tomography and histological analyses after 4 weeks showed that microparticle‐incorporated constructs with or without growth factor promoted greater bone formation compared to sham controls, with the greatest degree of healing with bony bridging resulting from constructs loaded with BMP‐2 and TGF‐β1. Importantly, bone volume fraction increased significantly from 4 to 8 weeks in defects treated with both growth factors. Immunohistochemistry revealed the presence of types I, II, and X collagen, suggesting defect healing via endochondral ossification in all experimental groups. The presence of vascularized red bone marrow provided strong evidence for the ability of these constructs to stimulate angiogenesis. This system has great translational potential as a readily implantable combination therapy that can initiate and accelerate endochondral ossification in vivo. Importantly, construct implantation does not require prior lengthy in vitro culture for chondrogenic cell priming with growth factors that is necessary for current scaffold‐free combination therapies. Stem Cells Translational Medicine 2017;6:1644–1659 A readily implantable scaffold‐free system comprised of human bone marrow‐derived mesenchymal stem cells (hMSCs) embedded with bioactive microparticles capable of controlled delivery of TGF‐β1 and bone morphogenetic protein‐2 was engineered to drive endochondral bone formation in rat calvarial defects. Micro‐computed tomography and histological analyses demonstrated that scaffold‐free hMSC constructs promoted bone bridging of the defects after 4 and 8 weeks.

This comprehensive review paper describes recent advances made in the field of electrochemical nanobiosensors for the detection of breast cancer (BC) biomarkers such as specific genes, microRNA, proteins, circulating tumor cells, BC cell lines, and exosomes or exosome-derived biomarkers. Besides the description of key functional characteristics of electrochemical nanobiosensors, the reader can find basic statistic information about BC incidence and mortality, breast pathology, and current clinically used BC biomarkers. The final part of the review is focused on challenges that need to be addressed in order to apply electrochemical nanobiosensors in a clinical practice.

We demonstrate that the introduction of an elemental beam of Mn during the molecular beam epitaxial growth of Bi2Se3 results in the formation of layers of Bi2MnSe4 that intersperse between layers of pure Bi2Se3. This study revises the assumption held by many who study magnetic topological insulators (TIs) that Mn incorporates randomly at Bi-substitutional sites during epitaxial growth of Mn:Bi2Se3. Here, we report the formation of thin film magnetic TI Bi2MnSe4 with stoichiometric composition that grows in a self-assembled multilayer heterostructure with layers of Bi2Se3, where the number of Bi2Se3 layers separating the single Bi2MnSe4 layers is approximately defined by the relative arrival rate of Mn ions to Bi and Se ions during growth, and we present its compositional, structural, and electronic properties. We support a model for the epitaxial growth of Bi2MnSe4 in a near-periodic self-assembled layered heterostructure with Bi2Se3 with corresponding theoretical calculations of the energetics of this material and those of similar compositions. Computationally derived electronic structure of these heterostructures demonstrates the existence of topologically nontrivial surface states at sufficient thickness.