[16p-A304-1~13] 13.9 Compound solar cells

[16p-A304-13] Preparation of Cu₃N thin film by RF magnetron sputtering
and observation of p-type conduction by N₂ annealing

〇Haruki Nakamura¹, Ishikawa Hiroyasu^1,2, Fujinaka Masato¹, Katagiri Sho¹ (1.Shibaura Inst., 2.Int. Res. Center for Green Electronics)

Keywords:Cu3N, p-type

In this study, Cu₃N thin films prepared by RF magnetron sputtering were annealed in N₂ to investigate variations in physical properties. In XRD analysis, no significant change in XRD FWHM was observed in the N₂-annealed samples. Thermoelectromotive force measurements showed that both positive and negative voltages were observed in the as-depo. sample and polarity could not be determined, while a negative voltage was observed on the heated side in the N₂ annealed sample, indicating a p-type. I-V measurements showed a decrease in resistance for N₂-annealed samples. In the activation energy determined from the Arrhenius plot of the resistance from RT to 150°C,, the as-depo. sample was 243 meV below 75°C (low-temperature region) and 880 meV above 75°C (high-temperature region; considered the intrinsic region). The N₂-annealed samples were about 200 meV in both the low and high temperature regions. N₂ annealing increased acceptors, and the increase in carriers caused the intrinsic region shift to the higher temperature side. No change in XRD FWHM suggests that these variations are caused by structural changes at the microscopic level.