Thermoelectrics is an energy conversion technology from heat into electricity, and vice versa, through the thermoelectric phenomena in solids, while photovoltaics is an energy conversion technology from solar photon energy into electricity using the photo-excitations in solids. We are trying to find a way to combine thermoelectrics with photovoltaics to establish a new method to...
Glass and glass–ceramic electrolytes of (100 − x)(0.7Li2S·0.3P2S5)·xLiBr (x = 0, 5, 10, 12.5, 15 and 20) (mol %) were synthesized by mechanical milling and subsequent heat treatment. Glass powders with no crystal phase were obtained by mechanical milling. The conductivities of the glasses increased concomitantly with increasing LiBr content. The conductivity at x = 20 was 3.1...
Hollandite-type K1.88Ga1.88Sn6.12O16 and K1.58Ga1.58Ti6.42O16 powders obtained by the solid-state reaction method were examined by DRIFT spectroscopy to evaluate their NO adsorption properties. Two key findings were deduced from the refined structure information and evaluation of NO adsorption on a hollandite surface: first, the presence of oxygen in carrier gas contributed...
The efforts on dislocation reduction have become a potential issue to realize the future high-efficiency solar cells using the InGaN materials. In this work, first, a numerical simulation has been carried out for the reduction of dislocation density in wurtzite InGaN heteroepitaxy using step-graded interlayers. An energy balance model has been developed for evaluating the misfit...
NaTaO3––50 wt% Fe2O3 composite ceramics showed a large Seebeck voltage of −300 mV at a temperature gradient of 650 K yielding a constant Seebeck coefficient of more than −500 μV/K over a wide temperature range. We report for the first time that spark plasma sintering (SPS) at low temperature (870 K) could maintain the short-circuit current of −80 μA, which makes this...
Lithium ion capacitors (LICs) have recently received considerable attention as a new class of energy storage system because they possess the combined advantages of lithium ion batteries and supercapacitors. LICs typically consist of activated carbon cathodes and pre-lithiated graphite anodes. Despite the promising electrochemical performance, most LICs still hold room for further...
Pure Li4Ti5O12 with high crystallinity was successfully synthesized by a solvothermal process. The effects of initial Li/Ti ratio and post-heating temperature on the phase evolution, particle morphology and electrochemical properties were systematically investigated. Excess lithium, compared to the theoretical value in Li4Ti5O12, was required to get pure Li4Ti5O12 due to the...
The complex chemical hydride, ammonia borane (NH3BH3, AB) is a hydrogen rich compound. It is a promising hydrogen source for applications using proton exchange membrane fuel cells (PEMFCs) due to hydrogen content. It has reasonably lower operating temperatures compared with other solid-state hydriding materials. At present, AB is an expensive disposable source which in its pure...
Nanostructured and mesoporous cobalt oxide (Co3O4) nanowire in flower-like arrangements have been directly grown over flexible carbon cloth collectors using solvothermal synthesis for supercapacitor applications. Changes in the morphology and porosity of the nanowire assemblies have been induced by manipulating the calcination temperature (200–300 °C) of the one-dimensional (1-D...
Over the last years, the different polymorphs of MnO2 have been intensely studied as alternative compounds to amorphous hydrous RuO2 as supercapacitor electrode materials. In the present work, nanosized birnessite-type MnO2 platelets were synthesized via the polyol method followed by a subsequent ligand removal with NaOH. The resulting compound is easily dispersible in polar...
Texturing monocrystalline silicon (c-Si) for solar cell fabrication is still a key issue due to consumption of a large amount of costly isopropyl alcohol (IPA) in conventional NaOH/KOH solution. Controlling IPA amount in NaOH/KOH-texturing bath for longer life of the solution in industrial batch production is a difficult task. This article reports the use of a chemical bath with...
Based on the optical constants, calculations of optical losses in CdS/CdTe solar cells have been carried out taking into account reflections at the interfaces and absorption in the TCO and CdS layers. It has been shown that the losses caused by reflections at the interfaces result in lowering the short-circuit current by ~9 %, whereas absorption in the TCO and CdS layers with the...
Safe and ecological electrochemical double layer capacitors (EDLCs) are nowadays needed as energy sources for wearable electronics working in hard temperature conditions. Here, we report a method based on the use of an organic solvent without any surfactant to synthesize a self-supported paper-like electrode composed solely by multiwall carbon nanotubes, named buckypapers. Using...
Metal-organic vapor-phase epitaxial (MOVPE) growth of InGaN and InAlN has been studied to prepare a wanted band-gap from 0.65 to 2.5 eV for multi-junction tandem solar cells. The main subjects in the growth of InGaN are the suppression of phase separation and metallic In incorporation and the control of composition in grown films. Both phase separation and metallic In segregation...
The present communication reports the hydrogen storage characteristics of ZrMn2−xNi x laves phase hydrides. It is observed that promising hydrogen storage materials can be tailored when “x” is in the range of 1.5 ≤ x ≥ 1. The materials formed within this range reversibly store ~2 to ~3 H/F.U. under manageable operating conditions. The composition ZrMn0.5Ni1.5 is found to absorb...
Heterogeneous catalysts were developed from goat animal bones for biodiesel production via transesterification process. Desirable feedstock like peanut and rapeseed oils were chosen as raw material for the transesterification process. The bone catalysts calcined at 900 °C shows low crystallite size (41.47434 nm) and higher surface area (90.6523 m²/g) compared to catalysts...
Mg2Ni-based compounds were prepared using a high-energy milling technique, with a planetary ball mill, and subsequent annealing at 350 °C. X-ray diffraction analyses revealed that Mg2Ni phase was obtained after 10 milling hours, in addition to Ni phase. Increasing the ball-milling duration from 10 to 17 h causes a decrease in the crystal size of particles from 93 to 76 nm...
This review mainly focuses on summarizing the different metal oxide systems utilized for water-splitting reaction using concentrated solar energy. Only two or three cyclic redox processes are considered. Particle size effect on redox reactions and economic aspect of hydrogen production via concentrated solar energy are also briefly discussed. Among various metal oxides system...
Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF) powders were prepared by solution combustion synthesis using single and double fuels. The effect of the fuel mixture on the main properties of this well-known solid oxide fuel cell cathode material with high oxygen ion and electronic conduction was investigated in detail. Results showed that the fuel mixture significantly affected the area-specific...
Thin films and epitaxial hetero-structures of doped and undoped CeO2, and 8 mol% Y2O3 stabilized ZrO2 (YSZ), were fabricated by pulsed laser deposition on different single crystal substrates. Reflection high energy electron diffraction was used to monitor in situ the growth mechanism of the films. Two distinct growth mechanisms were identified along the (001) growth direction for...
The purpose of the present study is to investigate the performance enhancement of a shell and tube, latent heat thermal storage (LHTS) unit due to the addition of microsize copper particles in the phase change material (PCM). The thermo-physical properties of composites were experimentally obtained using Temperature-History technique. Numerical model was developed to explore the...
Microencapsulating a phase-change material (PCM) has become a prominent method of creating a stable environment in which the PCM can undergo its phase change without affecting the environment in which it is used. The method of encapsulation used in this study takes advantage of a new technology known as membrane emulsification and suspension polymerization. This study...
The review focus is on hydrogen production from renewables using photocatalysis. In particular we focus on the role of synergism on the reaction rate. Among the most studied examples for this phenomenon are catalysts based on TiO2. TiO2 exists in two common phases: anatase and rutile, with the latter more thermodynamically stable. For hydrogen production the photocatalyst is...
In order to avoid an unacceptably large efficiency loss when moving towards thinner silicon materials, the near-term challenge in the c-Si PV industry is to implement an effective passivation method for both cell surfaces. This paper discussed several suitable passivation schemes available. While the efficiency potential of industrially produced thin film poly-Si cells on foreign...