When prepared by a conventional evaporation technique, a film of platinum 33 nanometres thick will transmit only about 3 per cent of light. However, workers at two Bell establishments in Murray Hill, New Jersey have reported that the same thickness of film prepared by photoelectrodeposition onto indium phosphide can transmit as much as 92 per cent of light at wavelengths between 210 and 750 nm (A. Heller, D. E. Aspnes, J. D. Porter, T. T. Sheng and R. G. Vadimsky, J. Phys. Chem., 1985, 89, (21), 4444–4452).

Although this high transparency is due partially to porosity in the film, it is achieved mainly by controlling the microstructure of the deposit so that the particles which make up the film are small, compared with the wavelength of the light, and are not well connected.

The work reported may lead to several new areas of research.