Fabrication and characterization of hybrid photovoltaic devices based on N-type GaAs and polymer composites

Hybrid organic/inorganic solar cells have been fabricated and studied. The aim being to take advantage of the beneficial properties of both organic and inorganic materials. In this work we studied hybrid n-GaAs/Polymer photovoltaic devices and the effects of adding either carbon nanotubes or graphene into the polymer layer (either poly (3,4-ethyldioxythiophene):poly (styrenesulfunate) (PEDOT:PSS) or polyaniline (PANI)) to enhance its conductivity. We also investigated the use of two different metals (Al or Ag) as the anode electrode material to determine the influence of metal atoms migrating into the polymer layer on solar cell efficiency. The devices with the structure Al/PEDOT:PSS:MWCNT/n-GaAs/Au:Ge/Ni/Au exhibited the best performance, with a short circuit current (Jsc) of 28.6 mA/cm2 , an open circuit voltage (Voc) of 0.51 V, a fill factor (FF) of 29.8% and a power conversion efficiency (PCE) of 4.41% which is higher than other inorganic/organic hybrid devices reported in the literature. Based on optical absorption measurements and SEM analysis the solar cell performances reported here can mainly be attributed to photon absorption in both the doped PEDOT:PSS and the GaAs layers resulting in an increase of electron-hole pairs and improved the efficiency of the solar cells containing PEDOT:PSS in comparison with those containing PANI

Observations of low frequency admittance between isolated GaAs structures formed by ion implantation and by epitaxy on epitaxial buffer layers prepared at high and low temperatures

Comparisons have been made of the frequency dependence of the backgate admittance of GaAs structures prepared by MBE on undoped buffer layers prepared at high and low temperatures and of ion implanted structures. A model is offered to explain extra capacitive currents at low frequencies. Inductive and negative resistance behaviours which appear to be related have not been explained. None of these phenomena were apparent in the LT based structures

Post tonsillectomy pain: Can honey reduce the analgesic requirements?

Background: Tonsillectomy with or without adenoidectomy is one of the most common surgical procedures performed worldwide, especially for children. Oral honey administration following tonsillectomy in pediatric cases may reduce the need for analgesics via relieving postoperative pain. Objectives: The aim of this study was to evaluate the effects of honey on the incidence and severity of postoperative pain in patients undergoing tonsillectomy. Patients and Methods: A randomized, double blind, placebo controlled study was performed. One hundred and four patients, who were older than eight, and were scheduled for tonsillectomy, were divided into two equal groups, honey and placebo. Standardized general anesthesia, and postoperative usual analgesic, and antibiotic regimen were administrated for all patients. Acetaminophen plus honey for the honey group, and acetaminophen plus placebo for the placebo group were given daily. They began to receive honey or placebo when the patients established oral intake. Results: The difference between acetaminophen and acetaminophen plus honey groups was statistically significant both for visual analogue scale (VAS), and number of painkillers taken within the first three postoperative days. The consumption of painkillers differed significantly in every five postoperative days. No significant difference was found between groups regarding the number of awaking at night. Conclusions: Postoperative honey administration reduces postoperative pain and analgesic requirements in patients after tonsillectomy. As the side effects of honey appear to be negligible, consideration of its routine usage seems to be beneficial along with routine analgesics. © 2013 Iranian Society of Regional Anesthesia and Pain Medicine