P-type oxide based thin film transistors produced at low temperatures

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 SnOx films shows p-type conduction presenting a polycrystalline structure composed with a mixture of tetragonal beta-Sn and alpha-SnOx phases, after annealing at 200 degrees C. These films exhibit a hole carrier concentration in the range of approximate to 10(16)-10(18) cm(-3), electrical resistivity between 10(1)-10(2) Omega cm, Hall mobility of 4.8 cm(2)/Vs, optical band gap of 2.8 eV and average transmittance approximate to 85 % (400 to 2000 nm). Concerning copper oxide CuxO thin films they exhibit a polycrystalline structure with a strongest orientation along (111) plane. The CuxO 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 SnOx TFTs present field-effect mobility above 1.24 cm(2)/Vs (including the paper p-type oxide TFT) and an on/off modulation ratio of 10(3) while the CuxO TFTs exhibit a field-effect mobility of 1.3x10(-3) cm(2)/Vs and an on/off ratio of 2x10(2).