Acceptors in ZnO nanocrystals

Abstract

While zinc oxide (ZnO) has potential for optoelectronic applications, the lack of reliable p-type doping remains a major challenge. We provide evidence that ZnO nanocrystals contain uncompensated acceptors. IR absorption peaks at liquid-helium temperatures suggest a hydrogenic acceptor with a hole binding energy of 0.4–0.5 eV. Electron paramagnetic resonance (EPR) measurements in the dark showed a resonance at g=2.003, characteristic of acceptors that involve a zinc vacancy. An EPR resonance due to vacancy hydrogen complexes was observed after exposure to light. Given the lack of alternatives, vacancy complexes may provide a feasible route toward p-type conductivity.

Investigation of intrinsic defects in core-shell structured ZnO nanocrystals

“…Hence, comprehensive investigations of the fundamental properties of acceptors in ZnO and the study of surface defects on a nanoscale are needed. 9 Here, we demonstrate clearly how n-type ZnO can be transformed into p-type ZnO without doping. Such transformation of n-type ZnO nanocrystals could in principle offer a new approach to using p-type ZnO semiconductors in device technology.…”

Identification of intrinsic hydrogen impurities in ZnO with 1H solid-state nuclear magnetic resonance spectroscopy

“…http://dx.doi.org/10.1016/j.cplett.2015.03.024 0009-2614/© 2015 Elsevier B.V. All rights reserved.Bulk ZnO was obtained from Sinopharm Chemical Reagent Co., Ltd. Since the semiconductive properties of bulk ZnO and nanoparticles are different[39], we also prepared ZnO nanoparticles by mixing (C 2 H 5 ) 2 Zn (Sigma Aldrich 99%) and H 2 O. 18 L H 2 O was added into 1 mL 1 M (C 2 H 5 ) 2 Zn solution in n-hexane at room temperature with stirring under N 2 atmosphere to initiate a hydrolysis reaction.…”

Nitrogen deep accepters in ZnO nanowires induced by ammonia plasma

“…In fact, many sophisticated strategies have been employed to achieve suitable p-type doping in ZnO. [5][6][7][8][9][10][11][12][13] Among them, nitrogen has been considered as a promising p-type dopant of ZnO because of its similar ionic radius to oxygen. 14 Although nitrogen incorporation in ZnO has been intensively investigated experimentally and theoretically, the progress along this direction is slow, and nitrogen doping mechanisms and modes [15][16][17][18][19] are still controversial.…”