Analysis of strained double-lightly doped MOSCNT using NEGF

The effects of uniaxial and torsional strains on the double-lightly doped MOSCNT (DLD-MOSCNT) performances are investigated, using the non-equilibrium Green function (NEGF) formalism in mode space approach. The Hamiltonian of the device is obtained by a tight-binding approximation assuming that only p _z orbitals are contributing in carrier transport. In all simulation processes, one mode with the lowest subband is considered. DLD-MOSCNT has a small band-to-band tunneling and almost eliminates the ambipolar behavior of I _DS–V _GS characteristics because of the band engineering. We use a modified model to demonstrate the strain effects on such a low OFF-current device. The results show that the strain effects mainly depend on the chiral vector and diameter of CNT. The strain causes band gap and carrier velocity changes, which result in variation of ON- or OFF-current. In addition, the subthreshold swing of this device under uniaxial strain is calculated, which is about 61 mV/Dec for 2 % tensile strain in (16,0) and for ?2 % compressive strain in (17,0). Under the uniaxial strain, in the case that the energy band gap increases, the variation of DIBL is very small.     

Caustic Singularity in Ho?ava-Lifshitz Gravity

In this note we search for a family of solutions with Caustic singularity in non relativistic-renormalizable Hořava-Lifshitz (HL) theory without the general covariant. We show that in infrared (IR) limit and with a deviation from λ=1 we have no caustic singularity. Also in ultraviolet (UV) regime and for Ricci flat 3-dimensional (3d) spaces and codimension 1 and for λ≠1 the non linear terms should help bouncing this kind of most dangerous would be caustics. But if 3d curvature does not vanish, higher curvature terms do help caustics even in codimension one. Thus the arguments in (J. Cosmol. Astropart. Phys. 0909:005, 2009) are satisfied correctly.     

Redox-Bipolar Polyimide Two-Dimensional Covalent Organic Framework Cathodes for Durable Aluminium Batteries

Emerging rechargeable aluminium batteries (RABs) offer a sustainable option for next-generation energy storage technologies with low cost and exemplary safety. However, the development of RABs is restricted by the limited availability of high-performance cathode materials. Herein, we report two polyimide two-dimensional covalent organic frameworks (2D-COFs) cathodes with redox-bipolar capability in RAB. The optimal 2D-COF electrode achieves a high specific capacity of 132 mAh g⁻¹. Notably, the electrode presents long-term cycling stability (with a negligible ≈0.0007 % capacity decay per cycle), outperforming early reported organic RAB cathodes. 2D-COFs integrate n-type imide and p-type triazine active centres into the periodic porous polymer skeleton. With multiple characterizations, we elucidate the unique Faradaic reaction of the 2D-COF electrode, which involves AlCl²⁺ and AlCl₄⁻ dual-ions as charge carriers. This work paves the avenue toward novel organic cathodes in RABs.