UV radiation enhanced oxygen vacancy formation caused by the PLD plasma plume

TY - JOUR

T1 - UV radiation enhanced oxygen vacancy formation caused by the PLD plasma plume

AU - Hensling, F. V. E.

AU - Keeble, David

AU - Zhu, J.

AU - Brose, S.

AU - Xu, C.

AU - Gunkel, F.

AU - Danylyuk, S.

AU - Nonnenmann, S. S.

AU - Egger, W.

AU - Dittmann, R. W.

PY - 2018/6/11

Y1 - 2018/6/11

N2 - Pulsed Laser Deposition is a commonly used non-equilibrium physical deposition technique for the growth of complex oxide thin films. A wide range of parameters is known to influence the properties of the used samples and thin films, especially the oxygen-vacancy concentration. One parameter has up to this point been neglected due to the challenges of separating its influence from the influence of the impinging species during growth: the UV-radiation of the plasma plume. We here present experiments enabled by a specially designed holder to allow a separation of these two influences. The influence of the UV-irradiation during pulsed laser deposition on the formation of oxygen-vacancies is investigated for the perovskite model material SrTiO3. The carrier concentration of UV-irradiated samples is nearly constant with depth and time. By contrast samples not exposed to the radiation of the plume show a depth dependence and a decrease in concentration over time. We reveal an increase in Ti-vacancy–oxygen-vacancy-complexes for UV irradiated samples, consistent with the different carrier concentrations. We find a UV enhanced oxygen-vacancy incorporation rate as responsible mechanism. We provide a complete picture of another influence parameter to be considered during pulsed laser depositions and unravel the mechanism behind persistent-photo-conductivity in SrTiO3.

AB - Pulsed Laser Deposition is a commonly used non-equilibrium physical deposition technique for the growth of complex oxide thin films. A wide range of parameters is known to influence the properties of the used samples and thin films, especially the oxygen-vacancy concentration. One parameter has up to this point been neglected due to the challenges of separating its influence from the influence of the impinging species during growth: the UV-radiation of the plasma plume. We here present experiments enabled by a specially designed holder to allow a separation of these two influences. The influence of the UV-irradiation during pulsed laser deposition on the formation of oxygen-vacancies is investigated for the perovskite model material SrTiO3. The carrier concentration of UV-irradiated samples is nearly constant with depth and time. By contrast samples not exposed to the radiation of the plume show a depth dependence and a decrease in concentration over time. We reveal an increase in Ti-vacancy–oxygen-vacancy-complexes for UV irradiated samples, consistent with the different carrier concentrations. We find a UV enhanced oxygen-vacancy incorporation rate as responsible mechanism. We provide a complete picture of another influence parameter to be considered during pulsed laser depositions and unravel the mechanism behind persistent-photo-conductivity in SrTiO3.

UR - https://www.scopus.com/pages/publications/85048309215

U2 - 10.1038/s41598-018-27207-5

DO - 10.1038/s41598-018-27207-5

M3 - Article

C2 - 29892095

SN - 2045-2322

VL - 8

SP - 1

EP - 7

JO - Scientific Reports

JF - Scientific Reports

IS - 1

M1 - 8846

ER -