Sinc Research Articles

Enhancement of light emission of a low-resistivity silicon nanocrystal thin film: A simulational and experimental study

A silicon nanocrystal (Si NC) white light-emitting (λ = ∼400–900 nm) thin film with a relatively low resistivity of 1.6 × 104 Ω m has been prepared as an active medium for electrically driven Si light sources. The average size of Si NC is 2.4 ± 0.4 nm. To enhance the light emission efficiency of this low-resistivity Si NC thin film, approach of hydrogen passivation suitable for the traditional high-resistivity (1.2 × 107 Ω m in this work for example) red light-emitting Si NC thin film has been tried and found unavailable unfortunately. Our first principles simulation shows that Si NCs bonded to −O, −NH2, −OH, and −H ligands are responsible for red, green, and blue (RGB) primary color emissions in this white light-emitting sample, respectively. Passivation of the sample in NH3 and H2O atmosphere is then conducted, aiming to increase the number of the RGB light emitters. The light emission is significantly enhanced, with photoluminescence intensity, photoluminescence quantum yield, electroluminescence intensity, and net optical gains increased by factors of 4.6, 4.2, 4.0, and ∼3.0, respectively, after 10-day passivation. Further enhancements are expected for longer passivation.

Effect of lncRNA pvt1 on HBV replication in HepG2.2.15 cells, and its possible mechanism of action

Purpose: To investigate the influence of lncRNA pvt1 on hepatitis B virus replication in HepG2.2.15 cells and the underlying mechanism of action. 
 Methods: Concentrations of lncRNA pvt1 in HBV-positive liver cancer cell lines (HepAD38+, HepG2.2.15+, HepG2+, and HepaRG+), and 3 HBV-negative liver cancer cell lines were determined and compared. Differences in HBV DNA content, levels of HBsAg and HBeAg, and STAT3 axis signal pathway among groups were evaluated. 
 Results: LncRNA pvt1 levels in HBV-positive hepatoma cells were significantly higher than the corresponding expression levels in HBV-negative hepatoma cells. after si-pvt1 treatment in HepG2.2.15 cells, the 3.2K HBV DNA content increased significantly (p < 0.05), and the expression levels of HBsAg and HBeAg in HepG2.2.15 cells also significantly increased. In all groups, STAT3 protein level was comparable, but p-STAT3 protein expression in si-pvt1 group was significantly reduced, relative to those in Si NC and control groups (p < 0.05). 
 Conclusion: Levels of lncRNA pvt1 expression in HBV-positive and HBV-negative hepatoma cells differ significantly. Treatment with si-pvt1 decrease HBV DNA content in HepG2.2.15 cells through a mechanism that relates to the STAT3 axis signal pathway. This finding may be beneficial for follow-up treatment of HBV.

Device and Circuit Level Assessment of Negative Capacitance TFETs for Low-Power High-Performance Digital Circuits

In this paper, we propose and analyse the performance of negative capacitance tunnel field-effect-transistors (NC-TFETs) at device and circuit level. We design and simulate four NC-TFETs, two are Silicon based “Si NC N-TFET,” “Si NC P-TFET” and two are Heterojunction Silicon-Germanium source based “SiGe NC N-TFET,” “SiGe NC P-TFET.” The effect of NC is incorporated with 5 nm thick layer of ferroelectric Hafnium Zirconium Oxide HfZrO2 (FE-HZO) in gate stack of TFETs by using of Landau-Khalatnikov (L-K) equations in MATLAB. The results show that at reduced NC gate voltage, the ON current (ION), On to OFF current (ION/IOFF) in NC devices is enhanced by while reduction in the threshold voltage (VTH) and Average subthreshold slope (SSAV) is observed. The SiGe NC-TFETs showed the best response with maximum ION range, ION/IOFF ratio of lowest SS as compare to Si NC-TFETs. The circuit transient analysis is done using the Verilog-A model based on look-up table (LUT) approach. The propagation delay of NC NAND circuits is reduced 90%, the SiGe NC-TFETs based circuits showing the smallest propagation delay and fast transient characteristics. This paper also demonstrates that the impact of FE-HZO thickness (TFE) on the device-circuit characteristics.

Efficient Sensitized Photoluminescence from Erbium Chloride Silicate via Interparticle Energy Transfer.

In this study, we prepare Erbium compound nanocrystals and Si nanocrystal (Si NC) co-embedded silica film by the sol-gel method. Dual phases of Si and Er chloride silicate (ECS) nanocrystals were coprecipitated within amorphous silica. Effective sensitized emission of Er chloride silicate nanocrystals was realized via interparticle energy transfer between silicon nanocrystal and Er chloride silicate nanocrystals. The influence of density and the distribution of sensitizers and Er compounds on interparticle energy transfer efficiency was discussed. The interparticle energy transfer between the semiconductor and erbium compound nanocrystals offers some important insights into the realization of efficient light emission for silicon-based integrated photonics.

THE INFLUENCE OF THE MAIN TILLAGE SYSTEM ON THE PRODUCTIVITY OF SUNFLOWER HYBRIDS

The article highlights the solution of important scientific issues - increasing the yield of sunflower hybrids by applying the optimal system of basic tillage in the context of global climate change. The research was carried out in 2021 in the experimental field of VNAU on the basis of NDG "Agronomichne", which is located in the village of Agronomichne, Vinnytsia region. We studied three methods of basic tillage for sunflower crops - plowing to a depth of 23-25 cm (control), mouldboardless loosening - deep cultivator to a depth of 14-16 cm and surface disk tillage to a depth of 10-12 cm in the cultivation of sunflower hybrids of different maturity groups SI Arco, Alcantara and NC Brio). The best conditions for growth and development of sunflower plants were created in the variant where the mouldboard tillage was carried out with a plow PLN-3-35 to a depth of 23-25 cm and the whole period the cultivated plants were without competition from weeds for life factors - SI Arko - 143 cm, Alcantara - 158 cm and NC Brio - 177 cm. It should also be noted the increase in the height of sunflower plants with the extension of the growing season. The height of plants in the early-ripening hybrid of sunflower SI Arco in 2021 ranged from 122-143 cm, middle-early Alcantara - 142-158 cm and medium-ripe NK Brio - 160-177 cm, i.e. was the highest. Shallow and surface tillage with disc implements increases vegetative weeds by 2.3 and 2.8 times, respectively. The implementation of protective mechanized measures for sunflower sowing against weeds has contributed to a significant reduction in their number. Thus, in the control variant with shelf plowing with PLN-3-35 plow to a depth of 23-25 cm in the flowering phase of the basket, it was in the hybrid of sunflower SI Arco - 28 pcs. / m2, Alcantara - 45 pcs. / m2 and NK Brio - 25 pcs. ./m2, on the version with shelf-free loosening with a deep ripper "Bravo Till" to a depth of 14-16 cm - 75 pcs./ m2, 83 and 78 pcs./ m2, and with surface disk tillage harrow BDT-7 to a depth of 10-12 cm were the highest - 127 units / m2, 134 and 119 units / m2. Against the background of plowing, their number decreased by 31.2-42.8%. Carrying out mechanical measures (one before ladder and one after ladder harrowing, as well as inter-row loosening in the phase of 5-6 leaves of sunflower) protection of sunflower against the background of plowing helped to reduce weeds by 21.0-33.6%. At the end, plowing yield of sunflower seeds was higher (by 0.21-0.74 t / ha). The value of oil content when using mouldboard plowing was the highest and was in SI Arco - 46.4%, Alcantara - 47.2% and NC Brio - 47.4%.

Effects of thermal annealing on the distribution of boron and phosphorus in p-i-n structured silicon nanocrystals embedded in silicon dioxide

Thermal annealing temperature and time dictate the microstructure of semiconductor materials such as silicon nanocrystals (Si NCs). Herein, atom probe tomography (APT) and density functional theory (DFT) calculations are used to understand the thermal annealing temperature effects on Si NCs grown in a SiO2 matrix and the distribution behaviour of boron (B) and phosphorus (P) dopant atoms. The APT results demonstrate that raising the annealing temperature promotes growth and increased P concentration of the Si NCs. The data also shows that the thermal annealing does not promote the incorporation of B atoms into Si NCs. Instead, B atoms tend to locate at the interface between the Si NCs and SiO2 matrix. The DFT calculations support the APT data and reveal that oxygen vacancies regulate Si NC growth and dopant distribution. This study provides the detailed microstructure of p-type, intrinsic, and n-type Si NCs with changing annealing temperature and highlights how B and P dopants preferentially locate with respect to the Si NCs embedded in the SiO2 matrix with the aid of oxygen vacancies. These findings will be useful towards future optoelectronic applications.

Electroforming of Si NCs/p-Si photovoltaic devices: Enhancement of the conversion efficiency through resistive switching

In this work, the relation between the photovoltaic and resistive switching (RS) properties of metal-oxide-semiconductor devices containing Si nanocrystal (Si NC) superlattices is investigated. A first approximation concludes that the low resistance state achieved by the RS process allows for enhanced photogenerated carrier extraction when compared to the high resistance state and pristine devices. By using different current compliance values during the electroforming process, the low resistance state is further modified, improving its conductivity and the collection probability of photogenerated carriers. Conversion efficiency is enhanced by at least one and up to five orders of magnitude by applying different electroforming processes. In addition to promoting the RS properties in these devices, spectral response measurements demonstrate that Si NCs are partially responsible for the optical absorption, and that their contribution is maintained after electroforming. We thus conclude that the proposed methodology can improve the conversion efficiency of this and other multijunction solar cells or structures that also exhibit RS properties. Through RS, a dense network of conductive filaments is promoted in the insulating region, which reduces the travel distance of photocarriers for their collection.

Luminescence of silicon and quartz crystals at mechanical destruction

Spectra and time dependencies of fractoluminescence (FL) signals of silicon (Si) and quartz (SiO2) crystals are obtained when diamond crystals are scratched on their surfaces. Signals are generated when barriers preventing dislocation movement along sliding planes are broken. Simultaneously, the Si and SiO2 crystals break down into nanocrystals (nc). The band 1.62 eV and 2.14 eV corresponds in FL spectra of Si and SiO2 nc accordingly. After the crystals are broken, powders are formed. The size of Si and SiO2 nc in powders was determined by photoluminescence (PL) and Raman spectroscopy.

Effects of lncRNA-HEIH on proliferation, apoptosis and invasion of gastric cancer cells.

The aim of this study was to explore the expression of long non-coding ribonucleic acid HEIH (lncRNA-HEIH) in gastric cancer (GC) tissues, and to investigate its effects on the proliferation, apoptosis and invasion of HGC-27 cells. A total of 80 tissue samples were collected from patients diagnosed with GC in Shenzhen People's Hospital. Meanwhile, para-carcinoma tissues were enrolled as normal controls (Control group). Total RNA was extracted from tissues, and the expression of lncRNA-HEIH was detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). HGC-27 cells were cultured and transfected with small-interfering RNA-HEIH (si-HEIH group). At 48 h after transfection, cell proliferation, apoptosis and invasion were detected via methyl thiazolyl tetrazolium (MTT) assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and transwell assay, respectively. (1) Compared with Control group, the expression of lncRNA-HEIH rose significantly in GC tissues (p<0.01). (2) The expression of lncRNA-HEIH in HGC-27 cells was significantly down-regulated in si-HEIH group compared with si-NC group (p<0.01). (3) Compared with those in si-NC group, the proliferation of HGC-27 cells was suppressed (p<0.05), while the apoptosis of HGC-27 cells was promoted (p<0.01) in si-HEIH group. (4) The invasion of HGC-27 cells was remarkably inhibited in Si-HEIH group than si-NC group (p<0.05). LncRNA-HEIH is highly expressed in GC patients, which affects the proliferation, apoptosis and invasion of GC HGC-27 cells.

The Carrier Transport Properties of B-Doped Si Nanocrystal Films with Various Doping Concentrations

B-doped hydrogenated amorphous silicon (a-Si:H) films with various doping concentrations were prepared by a plasma-enhanced chemical vapor deposition (PECVD) technique. After thermal annealing, the as-deposited samples, B-doped silicon nanocrystals (Si NCs), were obtained in the films. The electronic properties of B-doped Si NC films with various doping concentrations combined with the microstructural characterization were investigated. A significant improvement of Hall mobility rising to the maximum of 17.8 cm2/V·s was achieved in the Si NC film after B doping, which is due to the reduction of grain boundary (GB) scattering in the B-doped samples. With increasing the doping concentration, it was interesting to find that a metal-insulator transition (MIT) took place in the B-doped Si NC films with high doping concentrations. The different carrier transport properties in the B-doped Si NC films with various doping concentrations were investigated and further discussed with emphasis on the scattering mechanisms in the transport process.

Effects of circRNA_103993 on the proliferation and apoptosis of NSCLC cells through miR-1271/ERG signaling pathway.

Non-small cell lung cancer (NSCLC) accounts for more than 80% of lung cancer. CircRNA is a new type of non-coding RNA. CircRNA was found to be deeply involved in the regulation of NSCLC cells. However, the principle of CircRNA regulating NSCLC cells needs to be further explored. The relative mRNA expression levels of CircRNA_103993, miR-1271 and ERG were detected by quantificational real-time polymerase chain reaction (qRT-PCR) in NSCLC cells and human bronchial epithelial cell line HBE. Cell proliferation was detected by the Cell Counting Kit (CCK8) when NSCLC cells were transfected with si-CircRNA_103993, si-NC, miR-1271 mimics, miR-NC, LV-ERG, respectively. The apoptotic rate of NSCLC cells was measured by apoptotic assay and flow Cytometry. The relative mRNA and protein expression levels of PCNA and caspase-3 were detected by Western blot and qRT-PCR. CircRNA_103993 and ERG were significantly up-regulated while miR-1271 was significantly down-regulated in NSCLC cells. Knockdown of CircRNA_103993 and high expression of miR-1271 significantly inhibited NSCLC cell proliferation and promoted apoptosis. The double luciferin report showed that CircRNA_103993 served as a sponge of miR-1271 and miR-1271 could directly target ERG in NSCLC cells. More importantly, low expression of CircRNA_103993 increased the expression level of miR-1271, and high expression of miR-1271 decreased the expression level of ERG. Further experiments showed that miR-1271 inhibitors reversed the effect of si-CircRNA_103993 on proliferation and apoptosis of NSCLC cells. However, miR-1271 mimics significantly promoted the effects of si-CircRNA_103993 on the proliferation and apoptosis. Moreover, LV-ERG reversed the effect of miR-1271 mimics on proliferation and apoptosis of NSCLC cells. However, si-ERG significantly promoted the effects of miR-1271 mimics on the proliferation and apoptosis. CircRNA_103993 was highly expressed in NSCLC cells. CircRNA_103993 regulated proliferation and apoptosis of NSCLC cells by acting as a sponge of miR-1271. The CircRNA_103993 /miR-1271/ ERG axis had an important effect on the proliferation and apoptosis of NSCLC cells. Therefore, CircRNA_103993 may be a target for treating lung cancer.

About Trigonometric-Polynomial Bounds of Sinc Function

In this article, we establish sharp trigonometric-polynomial bounds for unnormalized sinc function.

Fluorescence quenching based detection of p-nitrophenol using luminescent silicon nanocrystals and insights into the quenching mechanism

We demonstrate a simple, rapid, selective and sensitive method for the detection of p-nitrophenol (pNP) using luminescent colloidal silicon nanocrystals (Si NCs). Aqueous suspension of green luminescent Si NCs was prepared at room temperature by simultaneous hydrolysis and redox reaction of (3-aminopropyl)triethoxysilane (APTES) in a remarkably simple one-step method. Trace addition of pNP significantly quenched the luminescence of the Si NCs and the quenching was found to be linearly dependent on the pNP concentration in the range of 0–20 μM of pNP in solution. Beyond 20 μM pNP concentration the quenching varied exponentially. Analysis of steady state absorption and emission, along with photoluminescence decay dynamics revealed that formation of ground state complexes (static quenching) and primary inner filter effect played a combined role in affecting quenching at relatively lower concentration range (0–20 μM); whereas both static and dynamic quenching came into effect at concentrations above 20 μM. Finally, we demonstrate a simple, pH-paper-type sensor based on Si NC coated filter paper and aluminium tape, for detection of aqueous as well as airborne pNP.

Study on the mechanism of long non-coding RNA migration inhibitory factor antisense RNA1 in regulating proliferation, invasion and metastasis of non-small cell lung cancer

Objective To explore the molecular mechanism by which long non-coding RNA (lncRNA) migration inhibitory factor antisense RNA1 (MIF-AS1)/microRNA (miRNAM miR)-370-3p/mitogen activated protein kinase 9 (MAP3K9) molecular axis regulates proliferation, invasion and migration of non-small cell lung cancer (NSCLC). Methods Twenty cancer samples of NSCLC patients were collected from Henan Provincial People’s Hospital from May 2017 to January 2019. There were 12 males and 8 females, aged (52.37±10.34) years. Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) and Western blotting were used to detect the expression levels of MIF-AS1, miR-370-3p and MAP3K9 in cancer tissues and 9 cell lines. NSCLC A549 cells were transfected with si-MIF-AS1, si-NC, si-MIF-AS1+ anti-miR-370-3p or si-MIF-AS1+ pcDNA-MAP3K9, respectively. Methyl thiazol tetrazolium (MTT) assay and Transwell assay were used to detect the proliferation, migration and invasion of transfected cells. Western blotting was used to detect the expression of Cyclin D1, p21, p27, matrix metalloproteinase (MMP)-2, MMP-9 and MMP-14 proteins. The dual luciferase reporter gene verified the targeting regulation of MIF-AS1 on miR-370-3p and miR-370-3p on MAP3K9. Results The expression of MIF-AS1 and MAP3K9 in NSCLC tissues (2.49±0.25 and 2.24±0.22) and A549 cells (2.54±0.24 and 2.31±0.23), H1299 cells (2.11±0.21 and 2.44±0.24) and PC-9 cells (2.26±0.23 and 2.16±0.22) was significantly higher than that in adjacent tissues (1.00±0.09 and 1.02±0.09) and normal lung epithelial cells BEAS-2B (1.01±0.09 and 1.00±0.09) (t=25.078, P<0.05; F=94.367, P<0.05). The expression of miR-370-3p in NSCLC tissues (0.42±0.04), A549 cells (0.34±0.03), H1299 cells (0.53±0.05), and PC-9 cells (0.44±0.04) was significantly lower than that in adjacent tissues (1.01±0.08) and BEAS-2B cells (1.00±0.08) (t=29.500, P<0.05; F=269.552, P<0.05). Transfection with si-MIF-AS1 significantly inhibited NSCLC cell proliferation (24 h: 0.27±0.03, 48 h: 0.36±0.03, 72 h: 0.48±0.04), invasion (24.33±3.14), migration (32.46±3.34) ability (P<0.01), up-regulated p21 (0.64±0.06), p27 (0.77±0.07) protein expression (t=17.441, P<0.05; t=17.726, P<0.05) and down-regulated Cyclin D1 (0.29±0.03), MMP-2 (0.25±0.03), MMP-9 (0.34±0.03) and MMP-14 (0.29±0.03) protein expression (t=17.732, P<0.05). The dual luciferase reporter gene confirmed that MIF-AS1 was bond to miR-370-3p and miR-370-3p was bond to MAP3K9. Transfection with si-MIF-AS1+ anti-miR-370-3p or si-MIF-AS1+ pcDNA-MAP3K9 inhibited the effects of si-MIF-AS1 on proliferation, invasion and migration of NSCLC cells. Conclusion LncRNA MIF-AS1 promotes proliferation, migration and invasion of NSCLCs by regulating miR-370-3p/MAP3K9 molecular axis. Key words: Non-small cell lung cancer; Long non-coding RNA migration inhibitory factor antisense RNA1; MicroRNA-370-3p; Mitogen activated protein kinase 9; Proliferation; Migration; Invasion

Effect of long-chain non-coding RNA TUG1 on radiosensitivity of human cervical cancer XB1702 cells by adsorption of miR-145

Objective To evaluate the effect of long-chain non-coding RNA TUG1 on the radiosensitivity of cervical cancer cells and explore its underlying mechanism. Methods The expression of TUG1 and miR-145 in cervical cancer cells XB1702 and normal endometrial stromal cells (ESCs) was detected by qRT-PCR. The transfected si-NC, transfected si-TUG1, transfected si-NC combined with irradiation, transfected si-TUG1 combined with irradiation, si-TUG1 and anti-miR-NC co-transfected and, si-TUG1 and anti-miR-145 co-transfected groups were established, which were transfected into XB1702 cells by liposome method. The survival fraction of each group was detected by colony formation assay. The cell apoptosis of each group was detected by flow cytometry. The fluorescence activity of each group was assessed by dual luciferase reporter gene assay. Results Compared with the normal ESCs, the expression of TUG1 was significantly up-regulated, whereas that of miR-145 was significantly down-regulated in the cervical cancer cells XB1702. Silencing TUG1 significantly increased the survival fraction of XB1702 cells, promoted cell apoptosis and enhanced the radiosensitivity of irradiation to XB1702 cells. TUG1 could target and regulate the expression of miR-145. Suppressing miR-145 reversed the silencing effect of TUG1 on inhibiting proliferation, accelerating apoptosis promotion and enhancing sensitization of XB1702 cells. Conclusions Silencing long-chain non-coding RNA TUG1 can enhance the radiosensitivity of cervical cancer cells. The mechanism may be related to targeting miR-145, which will provide a target for radiotherapy of cervical cancer. Key words: TUG1 gene; miR-145 gene; Radiosensitivity; Cervical cancer cell line

Electrically Stimulated Synaptic Resistive Switch in Solution-Processed Silicon Nanocrystal Thin Film: Formation Mechanism of Oxygen Vacancy Filament for Synaptic Function

We demonstrate an electrically stimulated synaptic resistive switch in a silicon nanocrystal (Si NC) thin film. A forming-free resistive switching occurs on the surface of natively oxidized Si NCs because of filaments of oxygen vacancies. To show a gradual change of the resistance, we investigate a formation mechanism of an oxygen vacancy filament. This gradual change in the resistance with input voltage pulses corresponds to short-term plasticity (STP) and long-term potentiation (LTP) in biological synapses. We simulate spike-timing-dependent plasticity (STDP) in the resistive switch by voltage pulses.

LncRNA-DANCR promotes growth and metastasis of colorectal cancer via activating epithelial-mesenchymal transition process

Background: The aim of this study was to investigate the effects and underlying mechanism of long non- coding RNA-differentiation antagonizing non-protein coding RNA (lncRNA-DANCR) on colorectal cancer (CRC). Methods: The expression of lncRNA-DANCR in CRC and pericarcinous tissues from 40 CRC patients, and the expression in HT-29 cells and FHC cells, were determined by qRT-PCR. Cell proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The migration and invasion of CRC cells were detected by wound healing assay and transwell assay, respectively. HT-29 cells were transfected and divided into three groups: BLANK group, si-NC group and si-DANCR group. After transfection, the expression of lncRNA-DANCR was detected by qRT-PCR. The expression of E-cadherin and vimentin was detected by western blot and immunofluorescence. The mice model of xenograft tumor was established and histological changes of lung lobes sections were measured by hematoxylin-eosin (HE) staining. Results: The expression of lncRNA-DANCR in CRC tissues and HT-29 cells was significantly higher than that in non-CRC tissues and FHC cells. Silencing lncRNA-DANCR could significantly inhibit the proliferation, invasion and metastasis of HT-29 cells. Western blot showed that the expression of E-cadherin increased significantly and vimentin decreased significantly after silencing lncRNA-DANCR. The same results were observed in immunofluorescence experiment. Silence of lncRNA-DANCR markedly suppressed the growth and metastasis of CRC. Conclusions: LncRNA-DANCR may facilitate the growth and metastasis of CRC by regulating the epithelial-mesenchymal transition (EMT) process.

Silicon nanocrystals-based electroluminescent resistive switching device

In the last few years, the emergence of studies concerning the resistive switching (RS) phenomenon has resulted in the finding of a large amount of materials being capable of acting as an active layer in such devices, i.e., the layer where the change in resistance takes place. Whereas the normal operation consists of the electrical readout of the modified resistance state of the device after electrical writing, electro-photonic approaches seek the involvement of light in these devices, be it either for the active Set or Reset operations or the readout. We propose in this work silicon nanocrystal multilayers (Si NC MLs) as an active material for being used in RS devices, taking advantage of their outstanding optical properties. The resistance states of Si NC MLs were obtained by electrical excitation, whose readout is carried out by electrical and electro-optical means, thanks to a distinguishable electroluminescence emission under each state. To achieve this, we report on an adequate design that combines both the Si NC MLs with ZnO as a transparent conductive oxide, whose material properties ensure the device RS performance while allowing the electro-optical characterization. Overall, such an occurrence states the demonstration of a Si NCs-based electroluminescent RS device, which paves the way for their future integration into photonic integrated circuits.

Effects of surface functionalization and polymerization on anode characteristics of plasma-synthesized silicon nanocrystal active materials for lithium ion battery anode

We investigate the effects of surface functionalization and polymerization on the anode characteristics of plasma synthesized-silicon nanocrystal (Si NC) based active materials for anode of lithium ion batteries (LIBs). Surface functionalized Si NCs were synthesized by adopting capping molecule to the hydride-terminated Si NCs (H–Si NCs) via hydrosilylation, and polymerization with a silane agent to form artificial solid electrolyte interphase (SEI) layer capped Si NCs, which show a dramatic decrease in SEI layer resistance (Rsei). This result demonstrates the high potential of surface functionalized Si NCs as active materials in anode of LIBs.

Distribution of boron and phosphorus and roles of co-doping in colloidal silicon nanocrystals

Boron (B) and phosphorous (P) co-doped colloidal silicon nanocrystals (Si NCs) have unique size-dependent optical properties, which lead to potential applications in optoelectronic and biomedical applications. However, the microstructure of the B and P co-doped colloidal Si NCs – in particular, the exact location of the dopant atoms in real space, has not been studied. A lack of understanding of this underlying question limits our ability to better control sample fabrication, as well as our ability to further develop the optical properties. To study the microstructure, a process enabling atom probe tomography (APT) of colloidal Si NCs was developed. A dispersion of colloidal Si NCs in a SiO2 sol-gel solution and a low temperature curing are demonstrated as the key sample preparation steps. Our APT results demonstrate that a B-rich region exists at the surface of the Si NCs, while P atoms are distributed within the Si NCs. First principles density functional theory calculations of a Si NC embedded in SiO2 matrix reveal that P atoms, which always prefer to reside inside a Si NC, significantly influence the distribution of B atoms. Specifically, P atoms lower the B diffusion barrier at Si/SiO2 interface and stabilize B atoms to reside within individual Si NCs. We propose that the B-modified surface changes the chemical properties of the Si NCs by (i) offering chemical resistance to attack by HF and (ii) enabling dispersibility in solution without aggregation.