| Autor: |
Matsuzaki K; National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan., Chang CW; Department of Electrical and Computer Engineering, Jacobs School of Engineering, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093, United States., Nagafuji T; Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan., Tsunoda N; Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan., Kumagai Y; Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan., Nomura K; Department of Electrical and Computer Engineering, Jacobs School of Engineering, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093, United States.; Materials Science and Engineering Program, Jacobs School of Engineering, University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093, United States., Oba F; Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.; MDX Research Center for Element Strategy, International Research Frontiers Initiative, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan., Hosono H; MDX Research Center for Element Strategy, International Research Frontiers Initiative, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.; National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan. |
| Abstrakt: |
Substitutional doping, involving the replacement of a host with an aliovalent impurity ion, is widely used to attain ambipolar controllability in semiconductors, which is crucial for device application. However, its effectiveness for p-type doping is limited in monovalent cation compounds due to the lack of suitable aliovalent (i.e., zerovalent) impurities. We propose an alternative approach for p- and n-type doping, mediated by the sizes of isovalent alkali metal impurities in Cu(I)-based semiconductors, such as copper nitride with an electron concentration of ∼10 15 cm -3 . Doping of isovalent Li with a smaller size to interstitial positions improves n-type conductivity, and electron concentration is controllable in the range of 10 15 to 10 18 cm -3 . In contrast, larger isovalent Cs and Rb impurities facilitate p-type conversion, resulting in a hole concentration controllability of 10 14 to 10 17 cm -3 . First-principles calculations indicate that Li is placed as an interstitial impurity acting as a shallow donor in conjunction with the formation of a neutral impurity on Cu defects. As the impurity size increases beyond the capacity of the vacant space, the formation of multiple acceptor-type Cu vacancies is enhanced owing to the repulsion between host Cu + and Cs + /Rb + impurities. Consequently, the Cs or Rb impurity is located at the sites of the N accompanied by six neighboring Cu vacancies, forming acceptor defect complexes. This size-dependent isovalent impurity doping scheme opens up an alternative avenue for advancement in optoelectronic devices using monovalent cation-based semiconductors. |
