c-axis-oriented ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_7$ (1:2:3) and ${\mathrm{YBa}}_2$${\mathrm{Cu}}_4$${\mathrm{O}}_8$ (1:2:4) thin films were charged with hydrogen at 463 K and a ${\mathrm{H}}_2$ pressure of 100 mbar. The hydrogen concentrations and depth profiles were measured with the ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ nuclear reaction method. In contrast to earlier studies on bulk samples where a constant ${\mathit{T}}_{\mathit{c},\mathrm{o}\mathrm{n}\mathrm{s}\mathrm{e}\mathrm{t}}$ is reported, we find in our 1:2:3 films that the superconducting transition temperature decreases continuously with increasing hydrogen concentration and that the transitions remain relatively sharp, e.g., ${\mathit{T}}_{\mathit{c},\mathrm{o}\mathrm{n}\mathrm{s}\mathrm{e}\mathrm{t}}$=38 K and Δ${\mathit{T}}_{\mathit{c}}$=6.2 K for [H]/cell≃0.6. The electrical resistivity and Hall-effect measurements in the normal state indicate that the main effect of hydrogen doping is a reduction of the charge carrier concentration, whereas the carrier mobility is not changed significantly. At an average hydrogen concentration of [H]/cell≃2 in both systems, a new hydride phase is observed, which for 1:2:3 is characterized by a c-axis expansion of 16% and for 1:2:4 by a c-axis expansion of 1.5%.

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