Molecular implantation using a laser-induced molecular micro-jet

Implantation of organic molecules into conductive organic or inorganic materials on the nanometre scale is one of the challenging problems in materials research that has to be solved. We have developed an advanced method of laser implantation suitable for producing organic molecular dots with sizes of a few hundred nanometres on organic and inorganic solid materials. This method involves transferring of organic molecules from a source film to a target material through a water-filled space-gap using a laser-induced molecular micro-jet. In this way, organic dots of Coumarin 6 (C6) molecules were successfully implanted into different target materials such as polymer, glass, copper, indium tin oxide (ITO), stainless steel, and so on. The shapes of the implanted dots as well as the shapes of the holes, caused by damage to the source or target films during laser irradiation, depended on whether water or air filled the space-gap between the films

Elucidating the Role of Surface Energetics on Charge Separation during Photoelectrochemical Water Splitting

Efficient photoelectrochemical (PEC) water splitting requires charge separation and extraction from a photoactive semiconductor. Such a charge transport process is widely believed to be dictated by the bulk energetics of the semiconductor. However, its dependence on surface energetics along the semiconductor/electrolyte interface remains an open question. Here, we elucidate the influence of surface energetics on the performance of a well-established Mo-doped BiVO4 photoanode whose surface energetics are regulated by the facet-selective cocatalyst loading. Surprisingly, photodeposition of RhOx and CoOx cocatalysts onto the {010} and {110} facets, respectively, strongly enhanced the charge-separation efficiency, in addition to improving the injection efficiency for water oxidation. Detailed optoelectrical simulations confirm that the synergistic enhancement of charge separation originates from the distinct effects of the cocatalyst loading on the surface energetics. This insight into the fundamental charge-separation mechanism in PEC cells provides a perspective for cell design and operation