Multifunctional Buffer Layer Engineering for Efficient and Stable Wide-Bandgap Perovskite and Perovskite/Silicon Tandem Solar Cells.

Inverted perovskite solar cells (PSCs) are preferred for tandem applications due to their superior compatibility with diverse bottom solar cells. However, the solution processing and low formation energy of perovskites inevitably lead to numerous defects at both the bulk and interfaces. We report a facile and effective strategy for precisely modulating the perovskite by incorporating AlOx deposited by atomic layer deposition (ALD) on the top interface. We find that Al3+ can not only infiltrate the bulk phase and interact with halide ions to suppress ion migration and phase separation but also regulate the arrangement of energy levels and passivate defects on the perovskite surface and grain boundaries. Additionally, ALD-AlOx exhibits an encapsulation effect through a dense interlayer. Consequently, the ALD-AlOx treatment can significantly improve the power conversion efficiency (PCE) to 21.80% for 1.66-electron-volt (eV) PSCs. A monolithic perovskite-silicon TSCs using AlOx-modified perovskite achieved a PCE of 28.5% with excellent photothermal stability. More importantly, the resulting 1.55-eV PSC and module achieved a PCE of 25.08% (0.04 cm2) and 21.01% (aperture area of 15.5 cm2), respectively. Our study provides an effective way to efficient and stable wide-bandgap perovskite for perovskite-silicon TSCs and paves the way for large-area inverted PSCs.

Efficient and Stable Inverted Perovskite Solar Modules Enabled by Solid-Liquid Two-Step Film Formation.

A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells. The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs. In this work, we adopted a solid-liquid two-step film formation technique, which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films. This method possesses the advantages of integrating vapor deposition and solution methods, which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform, large-area perovskite film. Furthermore, modification of the NiOx/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization. As a result, a large-area perovskite film possessing larger grains, fewer pinholes, and reduced defects could be achieved. The inverted PSM with an active area of 61.56 cm2 (10 × 10 cm2 substrate) achieved a champion power conversion efficiency of 20.56% and significantly improved stability. This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.

Hydrophobic Hydrogen-Bonded Polymer Network for Efficient and Stable Perovskite/Si Tandem Solar Cells.

The pursuit of highly efficient and stable wide-band gap (WBG) perovskite solar cells (PSCs), especially for monolithic perovskite/silicon tandem devices, is a key focus in achieving the commercialization of perovskite photovoltaics. In this study, we initially designed poly(ionic liquid)s (PILs) with varying alkyl chain lengths based on density functional theory calculations. Results pinpoint that PILs with longer alkyl chain lengths tend to exhibit more robust binding energy with the perovskite structure. Then we synthesized the PILs to craft a hydrophobic hydrogen-bonded polymer network (HHPN) that passivates the WBG perovskite/electron transport layer interface, inhibits ion migration and serves as a barrier layer against water and oxygen ingression. Accordingly, the HHPN effectively curbs nonradiative recombination losses while facilitating efficient carrier transport, resulting in substantially enhanced open-circuit voltage (Voc ) and fill factor. As a result, the optimized single-junction WBG PSC achieves an impressive efficiency of 23.18 %, with Voc as high as 1.25 V, which is the highest reported for WBG (over 1.67 eV) PSCs. These devices also demonstrate outstanding thermostability and humidity resistance. Notably, this versatile strategy can be extended to textured perovskite/silicon tandem cells, reaching a remarkable efficiency of 28.24 % while maintaining exceptional operational stability.

Multi-scale optical simulation of crystalline silicon solar cells by combining ray and wave optics.

Optical simulations allow the evaluation of the absorption, reflection, and transmission of each functional layer of solar cells and, therefore, are of great importance for the design of high-efficiency crystalline silicon (c-Si) solar cells. Here, a multi-scale simulation method (MSM) based on ray and wave optics is proposed to investigate the optical characteristics of c-Si solar cells. The ray and wave optical methods are first independently employed on inverted pyramid glass sheets, where the latter one can describe the size-dependent interfacial scattering characteristics more accurately. Then the optical properties of a c-Si solar cell with a tunnel oxide passivated carrier-selective contact configuration are studied by employing the MSM, where scattering at the interfaces is acquired by a finite-difference time-domain method (wave optics). Since the MSM can accurately simulate optical modes such as the Rayleigh anomaly, Bloch mode, and Mie resonances, the reflection and transmission spectra of the whole device are in good agreement with the measured data. The proposed MSM has proven to be accurate for structures with functional thin films, which can be extended to hybrid tandem devices with top-level cells consisting of stacks of layers with similar dimensions.

Target Therapy for Buried Interface Enables Stable Perovskite Solar Cells with 25.05% Efficiency.

The buried interface in perovskite solar cells (PSCs) is pivotal for achieving high efficiency and stability. However, it is challenging to study and optimize the buried interface due to its non-exposed feature. Here, a facile and effective strategy is developed to modify the SnO2 /perovskite buried interface by passivating the buried defects in perovskite and modulating carrier dynamics via incorporating formamidine oxalate (FOA) in SnO2 nanoparticles. Both formamidinium and oxalate ions show a longitudinal gradient distribution in the SnO2 layer, mainly accumulating at the SnO2 /perovskite buried interface, which enables high-quality upper perovskite films, minimized defects, superior interface contacts, and matched energy levels between perovskite and SnO2 . Significantly, FOA can simultaneously reduce the oxygen vacancies and tin interstitial defects on the SnO2 surface and the FA+ /Pb2+ associated defects at the perovskite buried interface. Consequently, the FOA treatment significantly improves the efficiency of the PSCs from 22.40% to 25.05% and their storage- and photo-stability. This method provides an effective target therapy of buried interface in PSCs to achieve very high efficiency and stability.

Thermally stable threshold selector based on CuAg alloy for energy-efficient memory and neuromorphic computing applications.

As a promising candidate for high-density data storage and neuromorphic computing, cross-point memory arrays provide a platform to overcome the von Neumann bottleneck and accelerate neural network computation. In order to suppress the sneak-path current problem that limits their scalability and read accuracy, a two-terminal selector can be integrated at each cross-point to form the one-selector-one-memristor (1S1R) stack. In this work, we demonstrate a CuAg alloy-based, thermally stable and electroforming-free selector device with tunable threshold voltage and over 7 orders of magnitude ON/OFF ratio. A vertically stacked 64 × 64 1S1R cross-point array is further implemented by integrating the selector with SiO2-based memristors. The 1S1R devices exhibit extremely low leakage currents and proper switching characteristics, which are suitable for both storage class memory and synaptic weight storage. Finally, a selector-based leaky integrate-and-fire neuron is designed and experimentally implemented, which expands the application prospect of CuAg alloy selectors from synapses to neurons.

Enhanced diffraction efficiency with angular selectivity by inserting an optical interlayer into a diffractive waveguide for augmented reality displays.

The overall efficiency and image uniformity are important criteria for augmented reality display. The conventional in-coupling grating design intending to improve only the first-order diffraction efficiency without considering the multiple interactions with diffracted light in the waveguide is insufficient. In this work, the back-coupling loss (BCL) on the in-coupling surface relief grating, and the power of light arriving at the out-coupling grating over that of incident light (denoted as optical efficiency in waveguide, OEW) are introduced for the design of in-coupling grating. A simple and effective method to increase diffraction efficiency with unique angular selectivity is demonstrated by inserting an interlayer between the waveguide and grating. The optimized average OEW and its uniformity under a field of view of 40° are increased from 8.02% and 24.83% to 8.34% and 35.02% by introducing a region-selective MgF2 interlayer.

Heterostructure Silicon Solar Cells with Enhanced Power Conversion Efficiency Based on Si x /Ni3+ Self-Doped NiO x Passivating Contact.

Developing efficient crystalline silicon/wide-band gap metal-oxide thin-film heterostructure junction-based crystalline silicon (c-Si) solar cells has been an attractive alternative to the silicon thin film-based counterparts. Herein, nickel oxide thin films are introduced as the hole-selective layer for c-Si solar cells and prepared using the reactive sputtering technique with the target of metallic nickel. An optimal Ni3+ self-doped NiO x film is obtained by tuning the reactive oxygen atmosphere to construct the optimized c-Si/NiO x heterostructure band alignment. A thin SiO x interlayer was further introduced to reduce the defect of the c-Si/NiO x interface with the UV-ozone (UVO) treatment. The constructed p-type c-Si/SiO x /NiO x /Ag solar cell exhibits an increase in the open voltage from 586 to 611 mV and achieves a 19.2% conversion efficiency.

Implementation of High-Dose-Rate, CT-Based Prostate Brachytherapy in an Academic Teaching Hospital and Residency Training Program.

Introduction Prostate brachytherapy provides the most durable local control for prostate adenocarcinoma among all radiation treatment options. However, likely due to decreased trainee familiarity with the technique and resource intensity, it has seen a decline in utilization. Here we outline our experience with starting a high-dose-rate (HDR) prostate brachytherapy program within a residency training program and present our outcome data. Methods Patients were identified and screened using clinical data and volume study for candidacy for brachytherapy implantation. Eligible candidates were implanted and subsequently had radiation planning and delivery in our clinic. Descriptive statistical analysis was performed on our outcomes and dosimetry data and presented in tabular form. Results Seventeen patients were treated for a total of 18 implants (one monotherapy). No implant was aborted. No acute urinary retention requiring catheterization or chronic urethral stricture occurred. Biochemical recurrence-free survival was 94% at a median follow-up of 28.5 months (range 8.2-50 months); the one failure occurred in a very high-risk patient at 37 months following treatment. Dosimetrically, prostate coverage, urethra sparing, and rectum sparing aims were met. Volumetric bladder aims were also met; however, the max point dose to the bladder neck was above the guideline. Conclusion Our department successfully implemented an HDR prostate brachytherapy program. Treatments were effective and there was no grade 3 toxicity to report.

Interfacial Engineering of Cu2O Passivating Contact for Efficient Crystalline Silicon Solar Cells with an Al2O3 Passivation Layer.

Passivating contacts that simultaneously promote carrier selectivity and suppress surface recombination are considered as a promising trend in the crystalline silicon (c-Si) photovoltaic industry. In this work, efficient p-type c-Si (p-Si) solar cells with cuprous oxide (Cu2O) hole-selective contacts are demonstrated. The direct p-Si/Cu2O contact leads to a substoichiometric SiOx interlayer and diffusion of Cu into the silicon substrate, which would generate a deep-level impurity behaving as carrier recombination centers. An Al2O3 layer is subsequently employed at the p-Si/Cu2O interface, which not only serves as a passivating and tunneling layer but also suppresses the redox reaction and Cu diffusion at the Si/Cu2O interface. In conjunction with the high work function of Au and the superior optical property of Ag, a power conversion efficiency up to 19.71% is achieved with a p-Si/Al2O3/Cu2O/Au/Ag rear contact. This work provides a strategy for reducing interfacial defects and lowering energy barrier height in passivating contact solar cells.

Post-annealing Effect on Optical and Electronic Properties of Thermally Evaporated MoOX Thin Films as Hole-Selective Contacts for p-Si Solar Cells.

Owing to its large work function, MoOX has been widely used for hole-selective contact in both thin film and crystalline silicon solar cells. In this work, thermally evaporated MoOX films are employed on the rear sides of p-type crystalline silicon (p-Si) solar cells, where the optical and electronic properties of the MoOX films as well as the corresponding device performances are investigated as a function of post-annealing treatment. The MoOX film annealed at 100 °C shows the highest work function and proves the best hole selectivity based on the results of energy band simulation and contact resistivity measurements. The full rear p-Si/MoOX/Ag-contacted solar cells demonstrate the best performance with an efficiency of 19.19%, which is the result of the combined influence of MoOX's hole selectivity and passivation ability.

A novel irinotecan-lipiodol nanoemulsion for intravascular administration: pharmacokinetics and biodistribution in the normal and tumor bearing rat liver.

Colorectal cancer is one of the most common cancers in the United States and treatment options are limited for patients who develop liver metastases. Several chemotherapeutic regimens have been used for transvascular liver-directed therapy in the treatment of colorectal liver metastases without clear evidence of superiority of one therapy over another. We describe the development of a novel nanoemulsion through combining irinotecan (IRI), a first line systemic agent used for the treatment of colon cancer, with lipiodol, an oily contrast medium derived from poppy seed oil, and evaluated its pharmacokinetic and biodistribution profile as a function of portal venous chemoembolization (PVCE) versus transarterial chemoembolization (TACE) delivery. The Tessari technique was used to create a stable emulsion (20 mg IRI mixed with 2 mL lipiodol) with resultant particle size ranging from 28.9 nm to 56.4 nm. Pharmacokinetic profile established through venous sampling in Buffalo rats demonstrate that the area under the curve (AUC0-∞) of IRI was significantly less after PVCE with IRI-lipiodol as compared to IRI alone (131 vs. 316 µg*min/mL, p-value = .023), suggesting significantly higher amounts of IRI retention in the liver with the IRI-lipiodol nanoemulsion via first-pass extraction. Subseqent biodistribution studies in tumor-bearing WAG/Rjj rats revealed more IRI present in the tumor following TACE versus PVCE (29.19 ± 12.33 µg/g versus 3.42 ± 1.62; p-value = .0033) or IV (29.19 ± 12.33 µg/g versus 1.05 ± 0.47; p-value = .0035). The IRI-lipiodol nanoemulsion demonstrated an acceptable hepatotoxicity profile in all routes of administration. In conclusion, the IRI-lipiodol nanoemulsion via TACE showed promise and warrants further investigation as an option for the treatment of metastatic colorectal cancer.

Radiopaque scaffolds based on electrospun iodixanol/polycaprolactone fibrous composites.

Grafts based on biodegradable polymer scaffolds are increasingly used in tissue-engineering applications as they facilitate natural tissue regeneration. However, monitoring the position and integrity of these scaffolds over time is challenging due to radiolucency. In this study, we used an electrospinning method to fabricate biodegradable scaffolds based on polycaprolactone (PCL) and iodixanol, a clinical contrast agent. Scaffolds were implanted subcutaneously into C57BL/6 mice and monitored in vivo using longitudinal X-ray imaging and micro-computed tomography (CT). The addition of iodixanol altered the physicochemical properties of the PCL scaffold; notably, as the iodixanol concentration increased, the fiber diameter decreased. Radiopacity was achieved with corresponding signal enhancement as iodine concentration increased while exhibiting a steady time-dependent decrease of 0.96% per day in vivo. The electrospun scaffolds had similar performance with tissue culture-treated polystyrene in supporting the attachment, viability, and proliferation of human mesenchymal stem cells. Furthermore, implanted PCL-I scaffolds had more intense acute inflammatory infiltrate and thicker layers of maturing fibrous tissue. In conclusion, we developed radiopaque, biodegradable, biocompatible scaffolds whose position and integrity can be monitored noninvasively. The successful development of other imaging enhancers may further expand the use of biodegradable scaffolds in tissue engineering applications.

Bilayer MoOX/CrOX Passivating Contact Targeting Highly Stable Silicon Heterojunction Solar Cells.

Molybdenum oxide (MoOX, X < 3) has been successfully demonstrated as an efficient passivating hole-selective contact in crystalline Si (c-Si) heterojunction solar cells because of its large bandgap (∼3.2 eV) and work function (∼6.9 eV). However, the severe performance degradation coming from the instability of the MoOX and its interfaces has not been well addressed. In this work, we started with a c-Si(p)/MoOX heterojunction solar cell that yielded a power conversion efficiency (PCE) of 15.86%, in which the MoOX film was synthesized by industry-compatible atomic layer deposition (ALD). The initial PCE dropped to 10.20% after 2 days because of severe migration of O and Ag at the MoOX/Ag interface. We solved this by the insertion of a CrOX layer between the MoOX layer and the Ag electrode. The solar cell was found to be stable for more than 8 months in air because of the suppression of interface degradation. Our work demonstrates an effective way of improving the stability of silicon solar cells with transition metal oxide carrier selective contacts.

In vivo performance of gold nanoparticle-loaded absorbable inferior vena cava filters in a swine model.

Absorbable inferior vena cava filters (IVCFs) offer a promising alternative to metallic retrievable filters in providing protection against pulmonary embolism (PE) for patients contraindicated for anticoagulant therapy. However, because absorbable filters are not radiopaque, monitoring of the filter using conventional X-ray imaging modalities (e.g. plain film radiographs, computed tomography [CT] and fluoroscopy) during deployment and follow-up is not possible and represents a potential obstacle to widespread clinical integration of the device. Here, we demonstrate that gold nanoparticles (AuNPs) infused into biodegradable filters made up of poly-p-dioxanone (PPDO) may improve device radiopacity without untoward effects on device efficacy and safety, as assessed in swine models for 12 weeks. The absorbable AuNP-infused filters demonstrated significantly improved visualization using CT without affecting tensile strength, in vitro degradation, in vivo resorption, or thrombus-capturing efficacy, as compared to similar non-AuNPs infused resorbable IVCFs. This study presents a significant advancement to the development of imaging enhancers for absorbable IVCFs.

Light Propagation in Flexible Thin-Film Amorphous Silicon Solar Cells with Nanotextured Metal Back Reflectors.

Nanostructured metal back reflectors (BRs) are playing an important role in thin-film solar cells, which facilitates an increased optical path length within a relatively thin absorbing layer. In this study, three nanotextured plasmonic metal (copper, gold, and silver) BRs underneath flexible thin-film amorphous silicon solar cells are systematically investigated. The solar cells with BRs demonstrate an excellent light harvesting capability in the long-wavelength region. With the combination of hybrid cavity resonances, horizontal modes, and surface plasmonic resonances, more incident light is coupled into the photoactive layer. Compared to the reference cells, the three devices with plasmonic BRs show lower parasitic absorptions with different individual absorption distributions. Both experimental and simulated results indicate that the silver BR cells delivered the best performance with a promising power conversion efficiency of 7.26%. These rational designs of light harvesting nanostructures provide guidelines for high-performance thin-film solar cells and other optoelectronic devices.

Preparation and Characterization of Epoxy/Alumina Nanocomposites.

Nano-alumina (Al2O3, 30 nm) particles were employed to reinforce and toughen epoxy resin. The effects of Al2O3 nanoparticles on the mechanical properties of the composites were investigated by tensile and impact tests. It shows that the mechanical properties of epoxy nanocomposites have been improved significantly. For the prepared nanocomposite with 3.0 wt.% of Al2O3 addition, the tensile strength, elongation at break and impact strength reached 74.83 MPa, 10.63% and 13.79 kJ/m², and were improved by 82.60%, 33.38% and 63.58%, respectively, compared with those of pure epoxy resin. The epoxy/Al2O3 nanocomposites also show good dielectric properties and excellent thermal stability under nitrogen atmosphere. Investigation of fractured surface of the obtained nanocomposites was carried out to study the dispersion of nanoarchitectonics Al2O3 with scanning electron microscopy.

Antitumor Efficacy of Liposome-Encapsulated NVP-BEZ235 Combined with Irreversible Electroporation for Head and Neck Cancer.

Irreversible electroporation (IRE) kills tumor cells by the delivery of short pulses of strong electric fields. However, the field strength decreases with distance from the treatment center. When IRE cannot eradicate the entire tumor mass, the surviving tumor cells can regrow. NVP-BEZ235 is a dual PI3K/mTOR inhibitor that has been administered orally in clinical trials. However, its hydrophobicity and poor water solubility make NVP-BEZ235 difficult to deliver to target areas. To improve its pharmacokinetics and therapeutic efficacy, we have encapsulated NVP-BEZ235 in a liposome (termed as L-BEZ). Our current study focuses on the long-term antitumor efficacy of IRE and intratumoral injection of L-BEZ in HN5 head and neck cancer xenografts in nude mice. We compared in vitro efficacy, as well as the effect on tumor size and growth rate in vivo, between IRE alone, IRE + oral BEZ, and IRE + L-BEZ over the course of two months. All animals in the control group were sacrificed by day 36, due to excess tumor burden. Tumors treated with IRE alone grew faster and larger than those in the control group. IRE + oral BEZ suppressed tumor growth, but the growth rate increased to that of the controls toward the end of 21 days. Only IRE + L-BEZ eradicated the tumor masses, with no palpable or extractable tumor mass observed after two months. The combination of IRE and L-BEZ could effectively eradicate tumors and prevent recurrence.

High Weight-Specific Power Density of Thin-Film Amorphous Silicon Solar Cells on Graphene Papers.

Flexible thin-film solar cells with high weight-specific power density are highly desired in the emerging portable/wearable electronic devices, solar-powered vehicles, etc. The conventional flexible metallic or plastic substrates are encountered either overweight or thermal and mechanical mismatch with deposited films. In this work, we proposed a novel substrate for flexible solar cells based on graphene paper, which possesses the advantages of being lightweight and having a high-temperature tolerance and high mechanical flexibility. Thin-film amorphous silicon (a-Si:H) solar cells were constructed on such graphene paper, whose power density is 4.5 times higher than that on plastic polyimide substrates. In addition, the a-Si:H solar cells present notable flexibility whose power conversion efficiencies show little degradation when the solar cells are bent to a radius as small as 14 mm for more than 100 times. The application of this unique flexible substrate can be extended to CuInGaSe and CdTe solar cells and other thin-film devices requiring high-temperature processing.

IC-2 Suppresses Proliferation and Induces Apoptosis of Bladder Cancer Cells via the Wnt/ß-Catenin Pathway.

BACKGROUND The Wnt/ß-catenin signaling pathway participates in many important tumorigeneses processes, including bladder cancer. The inhibition of abnormal activation of Wnt pathways might provide a new approach to tumor treatment. In the present study, we investigated the role of IC-2, a novel Wnt pathways small molecular inhibitor, in bladder cancer tumorigenesis. MATERIAL AND METHODS Bladder cancer cells were treated with various concentrations of IC-2 (0-5 µM) in vitro. The proliferation ability was measured using colony formation assay and apoptosis was measured using flow cytometry analysis. The protein expression was detected using Western blot analysis. Xenograft in vivo assay was performed to assess tumor growth. RESULTS IC-2 suppressed the proliferation and aggravated the apoptosis of bladder cancer cells in dose-dependent and time-dependent manners in vitro. Moreover, high concentrations of IC-2 inhibited the Wnt pathway-related protein expression levels, including ß-catenin, Cyclin D1, and TCF4. In vivo, administration of IC-2 in xenograft mice decreased the ß-catenin expression and reduced the tumor volume. CONCLUSIONS Our results validate the tumor-inhibition effect of IC-2 on bladder cancer in vivo and in vitro, providing a novel therapeutic strategy for bladder cancer.