Theory of Luminescence Spectra of High-Density Electron-Hole Systems: Crossover from Excitonic Bose-Einstein Condenstation to Electron-Hole BCS State

We present a unified theory of luminescence spectra for highly excited semiconductors, which is applicable both to the electron-hole BCS state and to the exciton Bose-Einstein condensate. The crossover behavior between electron-hole BCS state and exciton Bose-Einstein condensate clearly manifests itself in the calculated luminescence spectra. The analysis is based on the Bethe-Salpeter equation combined with the generalized random-phase-approximation, which enables us to consider the multiple Coulomb scattering and the quantum fluctuation associated with the center-of-mass motion of electron-hole pairs. In the crossover regime, the calculated spectra are essentially different from results obtained by the BCS-like mean-field theory and the interacting Boson model. In particular, it is found that the broad spectrum, arising from the recombination of electron-hole BCS state, splits into the P- and P_2-luminescence bands with decreasing the particle density. The dependence of these bands on the carrier density is in good agreement with experiments for highly excited semiconductors.Comment: 9 pages, 4 figures, To appear in Solid State Communication

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

High mobility solution-processed n-channel organic thin film transistors

N-channel organic thin-film transistors (OTFTs) based on N,N'-bis(n-octyl)-(1,7&1,6)-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI8-CN2) were fabricated using different semiconductor film deposition methods, dielectric materials, and device structures. It was found that top -contact OTFTs fabricated on Si-SiO2 substrates with drop-cast or vapor deposited films afford comparable electron mobilities (0.01-0.1 cm2/Vs), much larger than those based on spincoated PDI8-CN2 films (0.001 cm2/Vs). Furthermore, n-channel top-contact TFTs were fabricated using solution-processed PDI8-CN2 films and a UV-curable solution-processed polymeric dielectric. These devices exhibit typical gate leakage currents < 1nA for Vgate > 100V, which are negligible compared to the corresponding source/drain currents (> 0.1mA). OTFTs tested in ambient exhibit electron mobilities as high as 0.05-0.2 cm 2/Vs and Ion:Ioff ∼ 105. Furthermore, Isouroe-drain-Vgate hysterisis is negligible when the OTFTs were tested in both bias directions at different Vgate scan rates, demonstrating excellent insulator-semiconductor interfacial properties. Bottom-contact TFTs exhibit typical lower performance (∼ ×0.1)compared to the top-contact structure. All of the devices stored in air for several months exhibit no degradation of the device characteristics

Surface modification of chromatography adsorbents by low temperature low pressure plasma

Surface modification of chromatography adsorbents by low temperature low pressure plasm