P-type thin-film transistors (TFTs) using room temperature sputtered tin and copper oxide as a transparent oxide
semiconductor have been produced on rigid and paper substrates. The SnO<sub>x</sub> films shows p-type conduction presenting a
polycrystalline structure composed with a mixture of tetragonal β-Sn and α-SnO<sub>x</sub> phases, after annealing at 200 °C.
These films exhibit a hole carrier concentration in the range of ≈ 10<sup>16</sup>-10<sup>18</sup> cm<sup>-3</sup>, electrical resistivity between 101-102
Ωcm, Hall mobility of 4.8 cm<sup>2</sup>/Vs, optical band gap of 2.8 eV and average transmittance ≈ 85 % (400 to 2000 nm).
Concerning copper oxide Cu<sub>x</sub>O thin films they exhibit a polycrystalline structure with a strongest orientation along (111)
plane. The Cu<sub>x</sub>O films produced between an oxygen partial pressure of 9 to 75% showed p-type behavior, as it was
measured by Hall effect and Seebeck measurements. The bottom gate p-type SnO<sub>x</sub> TFTs present field-effect mobility
above 1.24 cm<sup>2</sup>/Vs (including the paper p-type oxide TFT) and an on/off modulation ratio of 10<sup>3</sup> while the Cu<sub>x</sub>O TFTs
exhibit a field-effect mobility of 1.3×10<sup>-3</sup> cm<sup>2</sup>/Vs and an on/off ratio of 2×10<sup>2</sup>.