Achieving Ultrahigh Breakdown Strength and Energy Storage Performance through Periodic Interface Modification in SrTiO₃ Thin Film

Abstract

A periodic layer structure consisting of sol-gel-derived SrTiO and anodized AlO has been designed and fabricated by interface engineering. Utilizing the anodized AlO to be the blocking layer, not only the local high electric field around the hole and crack defects could be significantly reduced but also, and equally important, the blocking layer undertaking higher electric field could effectively decrease the breakdown probability of a SrTiO layer based on the finite element analysis. As the sample has been modified, the barrier height of the charge carrier was increased through fitting the conductance activation energy ( H). In addition, the space charge-limited conductance mechanism was almost eliminated according to the fitted results in the ln E-ln J diagram, indicating that most of the charge carrier released from traps were blocked or isolated by the AlO layer. As a result of the periodic interface modification, the leakage current was decreased 2 orders of magnitude and the breakdown strength was enhanced from 144.13 to 754.23 MV m. More importantly, the ultimate energy density is up to 39.49 J cm, which is 1505% greater than the sample without interface modification.

Progress, Outlook, and Challenges in Lead‐Free Energy‐Storage Ferroelectrics

“…In two phase multilayers, in fact, materials with high ε would act as the blocking layer, which share higher electrical field than the other one . As shown in Figure c,d, this has also been clearly studied in Gao's work with the synthesizing SrTiO 3 Al 2 O 3 (STO‐AO) multilayers by sol–gel route, with the result of 1505% increment ESD of 39.49 J cm −3 in optimal STO‐AO multilayer than pure STO thin film as seen in Figure e . Except for film state materials, multilayer structure to enhance ferroelectric energy storage performances for ceramic bulks has also been reported.…”

“…[176] As shown in Figure 23c,d, this has also been clearly studied in Gao's work with the synthesizing SrTiO 3 Al 2 O 3 (STO-AO) multilayers by sol-gel route, with the result of 1505% increment ESD of 39.49 J cm −3 in optimal STO-AO multilayer than pure STO thin film as seen in Figure 23e. [177] Except for film state materials, multilayer structure to enhance ferroelectric energy storage performances for ceramic bulks has also been reported. (SrTiO 3 +Li 2 CO 3 )/(0.94Bi 0.54 Na 0.46 TiO 3 +0.06BaTiO 3 ) (STL/BNBT) multilayer ceramics have been prepared by the combination of tape-casting, lamination technique, and conventional sintering method in Yang's work, and breakdown Figure 23.…”

“…Reproduced with permission. [177] Copyright 2018, American Chemical Society. f) FES for the electrical trees' spread of STL/BNBT ceramic at different electrical fields.…”

“…Interface engineering can be found in either layered structure or core-shell structure, which exhibit positive effects in either obstructing electrical tree spread or enhancing polarization in specific situation. [164,165,175,177,178,183,184] Defect engineering and domain engineering are also active means for enhancing energy storage performances in both bulks and films, which are suitable for polarization enhancement. [55,64,132,183,185] Due to substrate effect and growth controllability, stress engineering and superlattice structure, which are also positive to improve Figure 24.…”

In Situ TEM Study of the Amorphous-to-Crystalline Transition during Dielectric Breakdown in TiO2 Film

“…[7][8] Experimentally, structural and chemical changes during dielectric breakdown are usually characterized post-breakdown and no sufficient details of the dynamic processes are presented. 7,[9][10][11][12][13] In situ observation and characterization of the breakdown process can provide valuable information that otherwise cannot be obtained.…”