p-Type Iodine-Doping of Cu3N and Its Conversion to γ-CuI for the Fabrication of γ-CuI/Cu3N p-n Heterojunctions

Electronic Materials

Theodoros Pavloudis¹  Joseph Kioseoglou¹  Andreas Othonos²  Matthew Zervos³  Argyris Tilemachou³ 

[1] Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece;Laboratory of Ultrafast Science, Department of Physics, School of Sciences, University of Cyprus, P.O. Box 20537, Nicosia 1678, Cyprus;Nanostructured Materials and Devices Laboratory, School of Engineering, University of Cyprus, P.O. Box 20537, Nicosia 1678, Cyprus;

关键词: copper nitride;    copper iodide;    semiconductors;    p-type doping;    p-n heterojunctions;   

DOI  :  10.3390/electronicmat3010002

来源: DOAJ

【 摘 要 】

Cu₃N with a cubic crystal structure is obtained in this paper by the sputtering of Cu under N₂ followed by annealing under NH₃: H₂ at 400 °C, after which it was doped with iodine at room temperature resulting into p-type Cu₃N with hole densities between 10¹⁶ and 10¹⁷ cm⁻³. The Cu₃N exhibited distinct maxima in differential transmission at ~2.01 eV and 1.87 eV as shown by ultrafast pump-probe spectroscopy, corresponding to the M and R direct energy band gaps in excellent agreement with density functional theory calculations, suggesting that the band gap is clean and free of mid-gap states. The Cu₃N was gradually converted into optically transparent γ-CuI that had a hole density of 4 × 10¹⁷ cm⁻³, mobility of 12 cm²/Vs and room temperature photoluminescence at 3.1 eV corresponding to its direct energy band gap. We describe the fabrication and properties of γ-CuI/TiO₂/Cu₃N and γ-CuI/Cu₃N p-n heterojunctions that exhibited rectifying current-voltage characteristics, but no photogenerated current attributed to indirect recombination via shallow states in Cu₃N and/or deep states in the γ-CuI consistent with the short (ps) lifetimes of the photoexcited electrons-holes determined from transient absorption–transmission spectroscopy.

【 授权许可】

Unknown