ABSTRACT
Two-dimensional materials (2DMs) are a promising alternative to complement and upgrade high-frequency electronics. However, in order to boost their adoption, the availability of numerical tools and physically-based models able to support the experimental activities and to provide them with useful guidelines becomes essential. In this context, we propose a theoretical approach that combines numerical simulations and small-signal modeling to analyze 2DM-based FETs for radio-frequency applications. This multi-scale scheme takes into account non-idealities, such as interface traps, carrier velocity saturation, or short channel effects, by means of self-consistent physics-based numerical calculations that later feed the circuit level via a small-signal model based on the dynamic intrinsic capacitances of the device. At the circuit stage, the possibilities range from the evaluation of the performance of a single device to the design of complex circuits combining multiple transistors. In this work, we validate our scheme against experimental results and exemplify its use and capability assessing the impact of the channel scaling on the performance of MoS2-based FETs targeting RF applications.
ABSTRACT
BioFETs based on two-dimensional materials (2DMs) offer a unique opportunity to enhance, at a low cost, the sensitivity of current biosensors enabling the design of compact devices compatible with standard CMOS technology. The unique combination of large exposed surface areas and minimal thicknesses of 2DMs is an outstanding feature for these devices, and the assessment of their behaviour requires combined experimental and theoretical efforts. In this work we present a 2D-material based BioFET simulator including complex electrolyte reactions and analysing different models for the electrolyte-molecule interaction. These models describe how the molecular charge is screened by the electrolyte ions when their distributions are modified. The electrolyte simulation is validated against experimental results as well as against the analytical predictions of the Debye-Hückel approximation. The role of the electrolyte charge screening as well as the impact of the interaction model on the device responsivity are analysed in detail. The results are discussed in order to conclude about the consequences of employing different interaction approximations for the simulation of BioFETs and more generally on the correct modelling of biomolecule-device interaction in BioFETs.
ABSTRACT
Autologous hematopoietic cell transplantation (AHCT) is the standard of care for young patients with relapsed/refractory (R/R) Hodgkin's lymphoma (HL). However, there is limited experience of its efficacy and feasibility in older patients. The characteristics and outcomes of 121 patients aged ≥50 years (42 of them are ≥60 years old) with R/R HL who underwent AHCT were reviewed. After a median follow-up of 3.1 years, overall survival (OS) and progression-free survival (PFS) at 5 years were 64 and 55 %, respectively, with no differences between 50-59-year-old and ≥60-year-old patients. Hematological and extra-hematological toxicities after AHCT were comparable between the two groups of age. In univariate analysis, poorer OS and PFS were associated with disease status other than complete remission, hematopoietic cell transplantation comorbidity index (HCT-CI) scores >1, and Charlson Comorbidity Index (CCI) scores >1. HCT-CI scores >1 were also associated with a higher risk of grade 3-4 extrahematologic toxicity. In multivariate analysis, HCT-CI and CCI remained significantly associated with OS and PFS after adjustment for disease status. Our data show that AHCT can be performed in selected patients with R/R HL ≥50 years with acceptable outcome and toxicity. Comorbidities appear to impact AHCT outcome more than age.
