Robust High-κ Response in Molecularly Thin Perovskite Nanosheets

• Published in: ACS nano 2010-09, Vol.4 (9), p.5225-5232
• Main Authors: Osada, Minoru, Akatsuka, Kosho, Ebina, Yasuo, Funakubo, Hiroshi, Ono, Kanta, Takada, Kazunori, Sasaki, Takayoshi
• Format: Article
• Language: English
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn101453v

Size-induced suppression of permittivity in perovskite thin films is a fundamental problem that has remained unresolved for decades. This size-effect issue becomes increasingly important due to the integration of perovskite nanofilms into high-κ capacitors, as well as concerns that intrinsic size effects may limit their device performance. Here, we report a new approach to produce robust high-κ nanodielectrics using perovskite nanosheet (Ca2Nb3O10), a new class of nanomaterials that is derived from layered compounds by exfoliation. By a solution-based bottom-up approach using perovskite nanosheets, we have successfully fabricated multilayer nanofilms directly on SrRuO3 or Pt substrates without any interfacial dead layers. These nanofilms exhibit high dielectric constant (>200), the largest value seen so far in perovskite films with a thickness down to 10 nm. Furthermore, the superior high-κ properties are a size-effect-free characteristic with low leakage current density (