Universal Tc depression by irradiation defects in underdoped and overdoped cuprates?

We report on a study of the influence of defects introduced in the CuO2 planes of cuprates in a wide range of hole dopings x. T-c and electrical resistivity rho(T) measurements have been performed on electron-irradiated YBa2Cu3O7-delta and Tl2Ba2CuO6+x single crystals. A universal scaling between the decrease in T, and Delta rho(2D) x n, where Delta rho(2D) is the increase of the 2D resistance induced by the defects and n is the carrier concentration equal to x, is found for all the samples investigated here. This demonstrates that the hole content is the relevant parameter to describe the transport properties all over the phase diagram, in contradiction with a recent suggestion of a change in the number of carriers from x to 1-x at the optimal doping. Moreover, the analysis of our data suggests that strong scattering persists on the overdoped side.