In this work we demonstrate the fabrication of germanium nanoparticle (NP) based electronics. The whole process chain from the nanoparticle production up to the point of inverter integration is covered. Ge NPs with a mean diameter of 33 nm and a geometric standard deviation of 1.19 are synthesized in the gas phase by thermal decomposition of GeH 4 precursor in a seeded growth process. Dispersions of these particles in ethanol are employed to fabricate thin particulate films (60 to 120 nm in thickness) on substrates with a pre-patterned interdigitated aluminum electrode structure. The effect of temperature treatment, polymethyl methacrylate encapsulation and alumina coating by plasma-assisted atomic layer deposition (employing various temperatures) on the performance of these layers as thin film transistors (TFTs) is investigated. This coating combined with thermal annealing delivers ambipolar TFTs which show an I on /I off ratio in the range of 10 2 . We report fabrication of n-type, p-type or ambipolar Ge NP TFTs at maximum temperatures of 450 1C. For the first time, a circuit using two ambipolar TFTs is demonstrated to function as a NOT gate with an inverter gain of up to 4 which can be operated at room temperature in ambient air.
Ge-Si alloy nanoparticles (NPs) covering the full range of compositions were studied in regard to their suitability as semiconducting channel layer in thin-film transistors (TFTs). Special focus is given to the influence of annealing and encapsulation techniques on the contact and channel properties. Therefore, electrical characterization methods separating contact from channel characteristics are highlighted and applied. It is demonstrated that appropriate passivation of the nanoparticle surfaces can improve the Ion/Ioff ratios by modulation of the density of free charge carriers and also can suppress hysteresis effects. Ge-rich NP alloys can generally be passivated more effectively regardless if passivation is done with solution-processed poly(methyl methacrylate) (PMMA) or by aluminum oxide (Al2O3) from Atomic Layer Deposition (ALD). Sufficient annealing improves the contact formation between aluminum electrodes and Ge-Si particles by modification of charge injection. The presented analysis leads to a better understanding interface and surface effects in porous nanoparticle semiconductors for application in TFT devices.
Inborn errors of immunity include multiple genetic abnormalities affecting different components of the innate and adaptive immune systems. More than 450 genes have been described so far including DNA repair defects which may result in predisposition to infections, but also malignancies, neurologic abnormalities and growth retardation. The group of patients with DNA repair and methylation defects exhibit impaired adaptive immunity, which increases susceptibility to infections due to impaired repertoire diversity. In this context, we aimed to investigate the TCRvβ repertoire and its interaction with clinical entities in a group of IEI patients with DNA repair defects including ATM, DCLRE1C, DNA-PRKDC, DNA ligase-4, and BLM. Thirty-nine patients with evidence of DNA repair defects and radiosensitivity and 15 age-matched healthy controls were included in this study. Peripheral lymphocyte subset and TCR-vβ repertoire analyses were performed by flow cytometry. To contrast TCR-repertoire in patients with DNA repair defects to healthy controls, we extracted data on lymphocyte phenotype, thymic function, immunoglobulins, and analysis of the TCRvβ repertoire from a prior study. The entire TCR-vβ repertoire was detected in all patients. However, compared with the control group, 9 of 24 clones (37.5%) were statistically significantly lower, whereas only 3 clones had high levels (p < 0.05). In addition, 62.5% of all clones had lower values than the control group. Some unique vβ clones have been associated with some clinical entities. Clonotypes associated with infections, autoimmunity and lymphoid proliferation were detected in the patient group. Lower TCR-vβ-9 and TCR-vβ23, higher TCR-vβ7.2 were detected in the patients with pneumonia (n = 13) (respectively p = 0.018, p = 0.044 p = 0.032). In addition, AT patients with pneumonia (n = 10) had a lower TCR-vβ-9 clone than patients without pneumonia (n = 25) (p = 0.008). In summary, we observed skewed clonal proliferation of most TCR-vβ clones in DNA repair defects, especially AT. In addition, our study demonstrated that some TCR-vβ clones might be predictive of some clinical entities. To further investigate the impact of the diversity of the TCR repertoire on the clinical phenotype, future studies should focus on the analysis of naïve and memory T cells, the detection of the source of oligoclonality, and the relationship between clonality and clinical entities.
Background Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive combined immunodeficiency. The phenotype is profound T-cell deficiency with variable B- and NK-cell functions and results in recurrent and persistent infections that typically begin in the first year of life. Neurologic findings occur in approximately two-thirds of patients. The mechanism of neurologic abnormalities is unclear. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for PNP deficiency. Methods We report here six patients from five unrelated families with PNP deficiency treated in two centers in Turkey. We evaluated the neurological status of patients and compared to post-transplantation period if available. Then we performed PubMed, Google Scholar, and Researchgate searches using the terms "PNP" and "hematopoietic stem cell transplantation" to find all reported cases of PNP transplantation and compared to our cohort. Results Six patients were treated in two centers in Turkey. One patient died from post-transplant complications. The other four patients underwent successful HSCT with good immune reconstitution after transplantation (follow-up 21–48 months) and good neurological outcomes. The other patient with a new mutation is still waiting for a matching HLA donor. Discussion In PNP deficiency, clinical manifestations are variable, and this disease should be considered in the presence of many different clinical findings. Despite the comorbidities that occurred before transplantation, HSCT currently appears to be the only treatment option for this disease. HSCT not only cures immunologic disorders, but probably also improves or at least stabilizes the neurologic status of patients.
Rectangular intrinsic Josephson junction mesa structures of superconducting Bi 2 Sr 2 CaCu 2 O 8+δ (Bi2212) can be used as a source of continuous, coherent and polarized terahertz (THz) radiation. THz emitting mesas are below a certain underdoped level of Bi2212. They have small Josephson critical current in contrast to optimally doped and overdoped Bi2212. We deposited Au/Co/Au multilayer top of mesa and obtained small critical current from mesas fabricated by as-grown Bi2212 single crystals due to injection of spin polarized current. The spin injection eliminates adjustment of doping level for successful THz emission.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.