Ruthenium oxide-carbon-based nanofiller-reinforced conducting polymer nanocomposites and their supercapacitor applications.

In this review article, we have presented for the first time the new applications of supercapacitor technologies and working principles of the family of RuO2-carbon-based nanofiller-reinforced conducting polymer nanocomposites. Our review focuses on pseudocapacitors and symmetric and asymmetric supercapacitors. Over the last years, the supercapacitors as a new technology in energy storage systems have attracted more and more attention. They have some unique characteristics such as fast charge/discharge capability, high energy and power densities, and long stability. However, the need for economic, compatible, and easy synthesis materials for supercapacitors have led to the development of RuO2-carbon-based nanofiller-reinforced conducting polymer nanocomposites with RuO2. Therefore, the aim of this manuscript was to review RuO2-carbon-based nanofiller-reinforced conducting polymer nanocomposites with RuO2 over the last 17 years

Effect of Thermal and Structural Disorder on the Electronic Structure of Hybrid Perovskite Semiconductor CH3NH3PbI3

In this Letter, we investigate the temperature dependence of the optical properties of methylammonium lead iodide (MAPbI(3) = CH3NH3PbI3) from room temperature to 6 K. In both the tetragonal (T > 163 K) and the orthorhombic (T < 163 K) phases of MAPbI3, the band gap (from both absorption and photoluminescence (PL) measurements) decreases with decrease in temperature, in contrast to what is normally seen for many inorganic semiconductors, such as Si, GaAs, GaN, etc. We show that in the perovskites reported here, the temperature coefficient of thermal expansion is large and accounts for the positive temperature coefficient of the band gap. A detailed analysis of the exciton line width allows us to distinguish between static and dynamic disorder. The low-energy tail of the exciton absorption is reminiscent of Urbach absorption. The Urbach energy is a measure of the disorder, which is modeled using thermal and static disorder for both the phases separately. The static disorder component, manifested in the exciton line width at low temperature, is small. Above 60 K, thermal disorder increases the line width. Both these features are a measure of the high crystal quality and low disorder of the perovskite films even though they are produced from solution