Search

Nanomaterial morphology, chemical composition and 1T′/2H crystal phase tuning is achieved in colloidal WxMo1−xSe2 nanosheets synthesised by a direct colloidal reaction.

Cadmium-free buffer layers deposited by a dry vacuum process are mandatory for low-cost and environmentally friendly Cu(In1-xGax)Se2 (CIGS) photovoltaic in-line production. Zn(O,S) has been identified as an alternative to the chemical bath deposited CdS buffer layer, providing comparable power conversion efficiencies. Recently, a significant efficiency enhancement has been reported for sputtered Zn(O,S) buffers after an annealing treatment of the complete solar cell stack; the enhancement was attributed to interdiffusion at the CIGS/Zn(O,S) interface, resulting in wide-gap ZnSO4 islands formation and reduced interface defects. Here, we exclude interdiffusion or island formation at the absorber/buffer interface after annealing up to 200 °C using high-resolution scanning transmission electron microscopy (HR-STEM) and energy-dispersive X-ray spectroscopy (EDX). Interestingly, HR-STEM imaging reveals an epitaxial relationship between a part of the Zn(O,S) buffer layer grains and the CIGS grains induced by annealing at such a low temperature. This alteration of the CIGS/buffer interface is expected to lead to a lower density of interface defects, and could explain the efficiency enhancement observed upon annealing the solar cell stack, although other causes cannot be excluded.

High-throughput flame spray pyrolysis directly affords a low-loading Pt catalyst supported on cerium oxide, which is an excellent material for selective semihydrogenation of C2H2 at 180 °C, exhibiting nearly complete conversion of C2H2 (98.2%) with high selectivity towards C2H4 (87.1%). Pt in this catalyst is atomically dispersed within cerium oxide, and this structural feature restricts C2H4 adsorption as π-bonded, known to promote C2H4 selectivity.

Cadmium-free buffer layers deposited by a dry vacuum process are mandatory for low-cost and environmentally friendly Cu(In

Magnetoelectric multiferroic nanocomposites are increasingly attracting attention from researchers and engineers due to their transformative technological potential. Many papers have so far reported a fundamental understanding and designs of new multiferroic nanocomposites, and their potential applications. However, many challenges for establishing and expanding their applications remain, for example, the development of an affordable fabrication process for nanocomposites which show room temperature multiferroics with robust coupling between ferroelectricity and magnetism is one of the highest demands. In this work, an affordable liquid phase based method to fabricate a magnetoelectric multiferroic nanocomposite film is reported. Ferroelectric BaTiO3 (BTO) nanotube arrays are fabricated via anodization and hydrothermal treatment, and then spin-coated with ferrimagnetic CoFe2O4 (CFO) to obtain a BTO–CFO nanocomposite film. The film exhibits not only room-temperature multiferroicity but also perpendicular magnetic anisotropy.

Micro-concentrator solar cells enable higher power conversion efficiencies and material savings when compared to large-area non-concentrated solar cells. In this study, we use materials-efficient area-selective electrodeposition of the metallic elements, coupled with selenium reactive annealing, to form Cu(In,Ga)Se2 semiconductor absorber layers in patterned microelectrode arrays. This process achieves significant material savings of the low-abundance elements. The resulting copper-poor micro-absorber layers’ composition and homogeneity depend on the deposition charge, where higher charge leads to greater inhomogeneity in the Cu/In ratio and to a patchy presence of a CuIn5Se8 OVC phase. Photovoltaic devices show open-circuit voltages of up to 525 mV under a concentration factor of 18 ×, which is larger than other reported Cu(In,Ga)Se2 micro-solar cells fabricated by materials-efficient methods. Furthermore, a single micro-solar cell device, measured under light concentration, displayed a power conversion efficiency of 5% under a concentration factor of 33 ×. These results show the potential of the presented method to assemble micro-concentrator photovoltaic devices, which operate at higher efficiencies while using light concentration.