Tyrian purple by ancient authors. Not much is known about the subsequent steps, and the actual ancient method for mass-producing the two murex dyes has not yet been successfully reconstructed; this special "blackish clotted blood" colour, which was prized above all others, is believed to be achieved by double-dipping the cloth, once in the indigo dye of "H. trunculus" and once in the purple-red dye of "B. brandaris". The Roman mythographer Julius Pollux, writing in the 2nd century AD, asserted ("Onomasticon" I, 45–49) that the purple dye was first discovered by the philosopher Heracles of Tyre, or rather, by his dog, whose
Dye-sensitized solar cell difference, so real-world differences are dominated by current production, J. Although the dye is highly efficient at converting absorbed photons into free electrons in the TiO, only photons absorbed by the dye ultimately produce current. The rate of photon absorption depends upon the absorption spectrum of the sensitized TiO layer and upon the solar flux spectrum. The overlap between these two spectra determines the maximum possible photocurrent. Typically used dye molecules generally have poorer absorption in the red part of the spectrum compared to silicon, which means that fewer of the photons in sunlight are usable for current generation. These