• Sasase, Masato
• Sim, Kihyung
• Shiah, Yushien
• Abe, Katsumi
• Iimura, Soshi
• Tsuji, Masatake

Abstract

<jats:title>Abstract</jats:title><jats:p>Metal halide perovskites (MHPs) are plausible candidates for practical p‐type semiconductors. However, in thin film transistor (TFT) applications, both 2D PEA<jats:sub>2</jats:sub>SnI<jats:sub>4</jats:sub> and 3D FASnI<jats:sub>3</jats:sub> MHPs have different drawbacks. In 2D MHP, the TFT mobility is seriously reduced by grain‐boundary issues, whereas 3D MHP has an uncontrollably high hole density, which results in quite a large threshold voltage (<jats:italic>V</jats:italic><jats:sub>th</jats:sub>). To overcome these problems, a new concept based on a 2D–3D core–shell structure is herein proposed. In the proposed structure, a 3D MHP core is fully isolated by a 2D MHP, providing two desirable effects as follows. (i) <jats:italic>V</jats:italic><jats:sub>th</jats:sub> can be independently controlled by the 2D component, and (ii) the grain‐boundary resistance is significantly improved by the 2D/3D interface. Moreover, SnF<jats:sub>2</jats:sub> additives are used, and they facilitate the formation of the 2D/3D core–shell structure. Consequently, a high‐performance p‐type Sn‐based MHP TFT with a field‐effect mobility of ≈25 cm<jats:sup>2</jats:sup> V<jats:sup>−1</jats:sup> s<jats:sup>−1</jats:sup> is obtained. The voltage gain of a complementary metal oxide semiconductor (CMOS) inverter comprising an n‐channel InGaZnO<jats:italic><jats:sub>x</jats:sub></jats:italic> TFT and a p‐channel Sn‐MHP TFT is ≈200 V/V at <jats:italic>V</jats:italic><jats:sub>DD</jats:sub> = 20 V. Overall, the proposed 2D/3D core–shell structure is expected to provide a new route for obtaining high‐performance MHP TFTs.</jats:p>

Topics

• density
• perovskite
• impedance spectroscopy
• grain
• mobility
• thin film
• semiconductor
• tin