[21p-B202-1~13] 13.9 Compound solar cells

[21p-B202-7] Preparation of Cu3N thin film by RF magnetron sputtering and observation of n-type conduction

〇Masato Fujinaka¹, Haruki Nakamura¹, Syo Katagiri¹, Hiroyasu Ishikawa^1,2 (1.Shibaura Inst. of Tech., 2.Int. Res. Center for Green Electronics)

Keywords:Cu3N thin film, RF magnetron sputtering, n-type conduction

We have prepared Cu3N thin films by RF magnetron sputtering, but they do not show clear polarity in electrical properties. In this study, we report improved electrical properties of RF-magnetron-sputtered Cu3N thin films by CF4 plasma treatment followed by annealing treatment, initially expecting the interstitial F atoms to make the films p-type. Thermo electromotive force measurement results showed that the as-depo. film had a low voltage of less than 1 mV on the high-temperature side and unstable positive and negative polarity. The plasma-treated and annealed film showed a relatively stable and slightly larger positive voltage, indicating the n-type. In addition, the room temperature resistance decreased by more than two orders of magnitude. The activation energy of the as-depo. film was 590 meV, while it decreased to 229 meV in the as-depo. film. The XRD result of the plasma-treated and annealed film showed CuO peaks. We believe that O atoms introduced during the process are responsible for the n-type conversion.