• Energy Research

We present the results of the spectral transmittance and reflectance of a SiO2/TiO2 1D photonic crystal deposited by Radio Frequency sputtering on a flexible polymeric substrate, which shows a blue-shift in its transmittance stopband proportional to the incidence angle when bent. An adjustable sample holder was designed to regulate the bending and keep the sample in a bent condition. Different angles of incidence were also achieved through variable angle reflectance, where an increase in incidence angle led to the blue-shift and narrowing of the transmittance stopband. We addressed the sample's resistance against bending wear and tear by comparing the transmittance spectra acquired for the flat sample before and after the measurements made in bent configurations. An important stability has been observed.

Thin films of cobalt sulfide (CoS) of thickness l < 10m have been employed as anodes of p-type dye-sensitized solar cells (p-DSCs) when P1-sensitized nickel oxide (NiO) was the photoactive cathode and /I - constituted the redox mediator. In the role of counter electrode for p-DSCs, CoS was preferred over traditional platinized fluorine-doped indium oxide (Pt-FTO) due to the lower cost of the starting materials (Co salts) and the easier procedure of deposition onto large area substrates. The latter process was carried out via direct precipitation of CoS from aqueous solutions. The photoconversion efficiency (η) of the corresponding device was 0.07%. This value is about 35% less than the efficiency that is obtained with the analogous p-DSC employing the Pt-FTO anode (η = 0.11). Unlike p-DSCs based on Pt-FTO anodes, the photoelectrochemical cells employing CoS electrodes showed that this anodic material was not able to sustain the photocurrent densities generated by P1-sensitized NiO at a given photopotential. Illumination of the p-DSCs with CoS anodes and P1-sensitized NiO cathodes actually induced the reverse bias of the photoelectrochemical cell with CoS behaving like a p-type semiconductor with no degeneracy. © 2017 IOP Publishing Ltd.

Main DSSC components, along with their most critical materials and related issues are reviewed and feasible alternatives are envisaged.

Tandem dye-sensitized solar cell shows higher photoconversion performances with respect to parent devices with single photoactive electrode thanks to careful photocurrent matching and complementarity of electrodes optical absorption.

AbstractIn the quest for a sustainable society, energy storage technology is destined to play a central role in the future energy landscape. Breakthroughs in materials and methods involving sustainable resources are crucial to protect humankind from the most serious consequences of climate change. Rechargeable batteries of all forms will be required to follow the path. Elements that are eligible to harmonically contribute to the development of a sustainable ecosystem and fulfil the demands of high energy density batteries include Na, K, Ca, Mg, Zn, and Al. Numerous research efforts are underway to explore new battery chemistries based on these elements and, depending on the field of application, different elements inherit different advantages and challenges. Full sustainability implies that the environmental friendliness of these systems must be characterized by a “cradle‐to‐grave” approach. In this context, the pursuit of global environmental and economical sustainability from mass production, raw materials, and technical challenges is discussed herein for the most recent battery concepts based on monovalent and multivalent metal anodes. A perspective on strategies and opportunities particularly around the development of all‐solid‐state system configurations is provided, and the most important obstacles to overcome in search of a more sustainable future for electrochemical energy storage are addressed.