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Summary To address the instability issues arising due to leaching of lead in the extensively explored MPX perovskite, in this study, we suggest replacement of the cation CH3NH3+ (M+) with a larger cation CH3CH2NH3+ (E+). The proposed material EPX (CH3CH2NH3PbX3; X = Br, Cl), due to the larger size of E+ cation, is expected to offer increased hindrance to the movement of lead ions through the lattice and thereby reducing its degradation against heat and moisture. This investigation unfolds that EPBr has a direct energy band gap of 2.045 eV at R with absorption coefficient above 1.8 × 104 cm−1 and SLME parameter as high as 21.5% for a film of thickness of 1 μm at ambient temperature of 300 K, which confirm its aptness as photovoltaic absorber material (PVA). The investigation also shows that n‐type EPCl has a direct energy band gap of 2.668 eV with the figure of merit (ZT) exceeding 0.95 and Seebeck coefficient (S) more than 700 μV/K that reaffirm its suitability as thermoelectric (TE) material. [ABSTRACT FROM AUTHOR]

Summary: Herein, we have discussed the ethyl‐ammonium based hybrid perovskite (viz. CH3CH2NH3PbI3 or EAPbI3) as the potential candidate material for the development of photovoltaic devices having low processing cost and high power conversion efficiency (PCE). To address the stability and environmental issues due to leaching of lead from MAPbI3, we urge to replace cation CH3NH3+ (MA+) with an appropriate cation CH3CH2NH3+ (EA+) and hope that the EAPbI3 perovskite would prove to be a stable and eco‐friendly photovoltaic absorber (PVA) material yielding high PCE. We have investigated physical properties like energy bandgap, electron density distribution and optical coefficients by FP‐LAPW+lo and density functional theory (DFT). The present study reveals that EAPbI3 has a direct energy bandgap of 1.55 eV with absorption coefficient exceeding 2 × 104 per cm, which confirms its suitability as PVA material. The dependence of thermoelectric (TE) coefficients on chemical potential and carrier concentration at various temperatures has also been discussed. We have also carried out the calculations of spectroscopic limited maximum efficiency (SLME) parameter (30.5%), and the thermodynamic (TD) properties in the realm of quasi‐harmonic approximation. A detailed investigation on some of the properties of EAPbI3 perovskite relevant to PVA material is being done for the first time, the present study may motivate researchers for more comprehensive theoretical and experimental investigations in search of stable and economically and environmentally viable PVA materials. [ABSTRACT FROM AUTHOR]

Using a hydrodynamic model of semiconductor plasmas, we report an analytical investigation of hot-carrier induced nonlinearity and its impact on the optical parameters (refractive index and absorption coefficient) of a magnetized, space-charge neutral group IV semiconductor. The carrier heating by the pump is assumed to induce nonlinearity in the medium through momentum transfer collision frequency ν of the carriers and space-charge neutrality of the medium. For the linear optical parameters (n[sub l], a[sub l]), both electrons and holes are found to contribute resonantly at high frequency of the pump (ω[sub 0]approx. ω[sub ce]). For the nonlinear optical parameters (n[sub 2], a[sub 2]), the holes contribute significantly in the low pump frequency regime (ω[sub 0]approx. ω[sub ch],) whereas in the high pump frequency regime (ω[sub 0]approx. ω[sub ce]), both kinds of carriers contribute resonantly in which a much larger contribution comes from the electrons. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Neurophysiological studies have recently documented multisensory properties in ‘unimodal’ visual neurons of the cat posterolateral lateral suprasylvian (PLLS) cortex, a retinotopically organized area involved in visual motion processing. In this extrastriate visual area, a region has been identified where both visual and auditory stimuli were independently effective in activating neurons (bimodal zone), as well as a second region where visually-evoked activity was significantly facilitated by concurrent auditory stimulation but was unaffected by auditory stimulation alone (subthreshold multisensory region). Given their different distributions, the possible corticocortical connectivity underlying these distinct forms of crossmodal convergence was examined using biotinylated dextran amine (BDA) tracer methods in 21 adult cats. The auditory cortical areas examined included the anterior auditory field (AAF), primary auditory cortex (AI), dorsal zone (DZ), secondary auditory cortex (AII), field of the rostral suprasylvian sulcus (FRS), field anterior ectosylvian sulcus (FAES) and the posterior auditory field (PAF). Of these regions, the DZ, AI, AII, and FAES were found to project to the both the bimodal zone and the subthreshold region of the PLLS. This convergence of crossmodal inputs to the PLLS suggests not only that complex auditory information has access to this region but also that these connections provide the substrate for the different forms (bimodal versus subthreshold) of multisensory processing which may facilitate its functional role in visual motion processing. [ABSTRACT FROM AUTHOR]

Hybrid halide Perovskites have been emerging as the innovative candidate in the development of optoelectronic devices. Ethyl-ammonium based hybrid halide perovskites have been admirable compounds regarding low band gap, high stability and non-toxic properties instead of methyl-ammonium based hybrid halide perovskites. Herein, we have investigated structural, electronic, optical and thermoelectric (TE) properties of ethyl-ammonium tin iodide (CH 3 CH 2 NH 3 SnI 3) by full-potential linearized augmented plane wave plus local orbital (FP-LAPW + lo) method as implemented in the WIEN2k code within the density functional theory (DFT). The PBE-GGA, PBE- sol -GGA and TB- mBJ -GGA exchange-correlation potentials have been used to calculate the density of states and band structure of ethyl ammonium tin iodide (EASnI 3) and found that it is a direct band gap semiconductor. We have calculated optical parameters such as dielectric function, absorption coefficient, refractive index, extinction coefficient, Eloss, optical reflectivity and optical conductivity for photon energies in the range 0–25 eV. We have also calculated transport coefficients (Seebeck coefficient, the figure of merit, power factor, electrical conductivity, thermal conductivity) as a function of carrier concentration, chemical potential and temperature. Most of the investigated parameters are being reported for the first time. The present study establishes that ethyl-ammonium tin iodide (EASnI 3) offers high absorption coefficient, high Seebeck coefficient, etc. This makes it a prospective material for cost effective photovoltaic device applications to overcome environmental instabilities. • Physical properties of ethyl-ammonium tin iodide (CH 3 CH 2 NH 3 SnI 3). • EASnI 3 is a direct band gap semiconductor. • Thermoelectric coefficients as a function of carrier concentration. • Thermal properties have been done within the quasi-harmonic approximation. [ABSTRACT FROM AUTHOR]

Importance: A challenge in treating subglottic stenosis is assessment of airway caliber before and after management. At present, surgeons lack a simple, efficient, and precise method of measuring subglottic stenosis intraoperatively. We present a novel, easily reproducible tool for measurement of the diameter, location, and length of subglottic stenosis during suspension laryngoscopy., Methods and Observations: A set of 5 Kirschner wires (30-cm length and 1.6-mm diameter) were bent 90° at both ends to produce a series of 10 short ends designed to measure airway diameter (0.3- to 2.1-cm length with 2-mm intervals). Short, bent ends of the measuring sticks were designed to measure airway diameter. Hash marks at 2-mm intervals were created along the long axis of the measuring sticks to measure subglottic stenosis length and location relative to the vocal cords. The measuring stick was tested in 10 adult patients undergoing suspension microlaryngoscopy for endoscopic treatment of subglottic stenosis between September 2012 and July 2013. The accuracy of the measuring stick was evaluated using an airway phantom. The measuring stick enabled easy and precise quantification of subglottic stenosis diameter (82.5% agreement with reference; interobserver agreement, r = 0.995; P < .001), length (72.5%; r = 0.995; P < .001) and location during suspension laryngoscopy., Conclusions and Relevance: The measuring stick is inexpensive and simple to construct. It allows for safe, accurate, and practical measurement of subglottic stenosis diameter, length, and location during suspension laryngoscopy.