CdSe-sensitized mesoscopic TiO2 solar cells exhibiting >5% efficiency: redundancy of CdS buffer layer
Good progress has been made in improving the power conversion efficiency of semiconductor-sensitized solar cells over the last few years; however, it is unclear exactly what role the buffer layer plays in CdS/CdSe sensitized cells. In this hot paper a team from National University of Singapore and Nanyang Technological University fabricated CdSe-sensitized TiO2 electrodes with nearly identical optical density to the best-performing CdS/CdSe electrodes. A careful comparison between CdSe and CdS/CdSe sensitized cells reveals that the CdSe-sensitized solar cells offer a better performance when light absorption is identical to that of CdS/CdSe cells, making the CdS buffer layer redundant. (J. Mater. Chem., 2012, 22, 16235-16242)
Electrochemically stimulated release of lysozyme from an alginate matrix cross-linked with iron cations
Electrochemically controlled drug release from stimuli-responsive materials offers a convenient method to control dosage for personalised medicine; however this requires the development of biologically safe, intelligent materials, to act as delivery systems. In this hot paper Evgeny Katz and co-workers at Clarkson University, USA, report an alginate matrix cross-linked with Fe3+ cations that releases lysozyme when an electrochemical signal is applied. The released lysozyme retains it biological activity and could be replaced in the system with protein-based drugs. The team say the switchable behaviour of the alginate hydrogel is based on the different interaction of Fe3+ and Fe2+ cations with alginate. (J. Mater. Chem., 2012, DOI: 10.1039/C2JM32008H, Advance Article)