The formation mechanism and stability of p-type N-doped Zn-rich ZnO films

Nitrogen-doped semiconducting oxides. Implications on photochemical, photocatalytic and electronic properties derived from EPR spectroscopy

“…On the other hand, ZnO seems a more promising candidate. For this system some success in obtaining p-type conduction [64][65][66] or ferromagnetic states 69 by N doping is asserted in the literature. However, as reported by T. M. Barnes et al, 65 the conduction property tends to decline over time, indicating a possible progressive rearrangement of the electronic structure.…”

“…62 A p-type behaviour has been reported in the case of N-ZnO lms prepared by annealing of sputtered oxynitride lms 63 or by magnetron sputtering, 64 even though these electronic properties seems to be unstable and decline over time. 65,66 On the basis of theoretical forecasts, N-ZnO based structures have also been considered as dilute magnetic semiconductors showing ferromagnetic interactions among nitrogen centers 67,68 and experimental observation of such a behaviour have already been reported in the literature. 69 Various techniques have been used to introduce nitrogen into the ZnO matrix, depending on the morphology of the bare system nitrogen has been successfully introduced in ZnO single crystals grown through a chemical vapor deposition process and successively annealed in a N 2 ow at high temperature (see below).…”

Investigation of the Effects of Rapid Thermal Annealing on the Electron Transport Mechanism in Nitrogen-Doped ZnO Thin Films Grown by RF Magnetron Sputtering

“…In ZnO films doped with nitrogen, the n-type conduction can be attributed to donors formed by interstitial zinc, Zn i , and oxygen vacancies, V O , whereas the p-type conduction can be related to the acceptors formed by zinc vacancies, V Zn , oxygen interstitial, O i , and nitrogen substituting oxygen in the O sublattice [ 18 , 46 , 47 ]. We have confirmed the presence of these kinds of defect states in ZnO:N films by the analysis of IRSE and FTIR spectra [ 25 ] and also by the Raman and PL spectroscopic results presented and discussed above in Sections 3.1 and 3.2 .…”

Effect of thermal treatment on points defects of Al-N codoped ZnO films

“…One of the big challenges is to control the p-type doping due to its high activation energy and the low solubility of acceptor dopants. Another feature of ZnO not favorable to the p-type doping is the presence of native defects such as interstitial and vacancies acting as an n-type doping, generating a phenomenon known as self-compensation [1][2][3]. Nitrogen is the doping elements frequently used in order to replace the oxygen atoms and consequently increases the hole concentration.…”

“…Chen et al [8] studied In-N codoped ZnO films grown on different substrates and they found that 540 ºC is the optimal temperature; may be, this is the explanation why Zeng et al [11] got p-conductivity in Al-N codoped ZnO films sputtered at 500 °C and Shinho et al [12] observed n-conductivity in Al-N codoped ZnO sputtered at 300 °C. Other studies used thermal annealing in order to ensure the nitrogen incorporation in oxygen sites (N O ) and to achieve p-type doping [3,7,10,[13][14][15][16][17]. Li et al [10] found that p-doping is gotten with post-annealing at 615 ºC during 25 minutes on Ag-N doped ZnO films.…”