J-V characteristics of sol-gel-prepared Zn2+doped LiNbO3

Herein, a stable LiNbO3 (LN) sol, with different Zn2+ contents, is prepared using ethanol niobium, lithium acetate and zinc acetate as starting materials, absolute ethanol as a solvent, and acrylic acid and benzoyl acetone (BzAcH) as additives. The influence of Zn2+ content on LN crystal structure, light transmittance and J-V curve characteristics is studied in detail. XRD results reveal that Zn2+ doping, with a molar content of less than 5%, does not influence the crystal structure of LN. SEM indicates that the grain size of LN films gradually increases with the increase of doping content. The surface quality of LN films becomes worse when the doping content of Zn2+ reaches 5%. Moreover, light transmittance tests show that the maximum light transmittance is attained at the doping amount of 3%. J-V curves demonstrate that Pt/LN/LNO(LaNiO3) structure shows excellent resistance switching (RS) effect due to the formation of Schottky barrier at the Pt/LN interface, which initially becomes prominent with the increase of Zn2+ content, followed by a gradual decrease. On the other hand, In/LN/LNO structure exhibits poor RS effect due to the unobvious Schottky barrier at In/LNO interface. Furthermore, J-V curves at different temperatures demonstrate that the RS effect of Pt/LN/LNO structure tends to deteriorate, while the refractive index of LN film increases with the decrease of temperature. Herein, the abovementioned RS phenomenon is analyzed and explained in terms of the relationship between interfacial barrier and doping amount of Zn2+, migration of oxygen vacancies, and the relationship between insulation property of LN films and temperature. The research results are of experimental and theoretical significance for practical applications of LN films.

Automated summary

A stable LiNbO3 (LN) sol with different Zn2+ contents was prepared and its influence on crystal structure, light transmittance, and J-V curve characteristics was studied. Zn2+ doping did not affect the crystal structure of LN, but increased the grain size of LN films. The highest light transmittance was achieved at a doping amount of 3%. The Pt/LN/LNO structure showed excellent resistance switching (RS) effect, while the In/LN/LNO structure exhibited poor RS effect. The RS effect deteriorated with decreasing temperature, and the refractive index of LN film increased.