The Effect of Dielectric Capping on Few-Layer Phosphorene Transistors: Tuning the Schottky Barrier Heights

Author

Han Liu ; Neal, A.T. ; Mengwei Si ; Yuchen Du ; Ye, Peide D.

Author_Institution

Birck Nanotechnol. Center, Purdue Univ., West-Lafayette, IN, USA

Volume

35

Issue

7

fYear

2014

fDate

Jul-14

Firstpage

795

Lastpage

797

Abstract

Phosphorene is a unique single elemental semiconductor with two-dimensional layered structures. In this letter, we study the transistor behavior on mechanically exfoliated few-layer phosphorene with the top-gate. We achieve a high ON-current of 144 mA/mm and hole mobility of 95.6 cm²/V·s. We deposit Al₂O₃ by atomic layer deposition (ALD) and study the effects of dielectric capping. We observe that the polarity of the transistors alternated from p-type to ambipolar with Al₂O₃ grown on the top. We attribute this transition to the changes for the effective Schottky barrier heights for both electrons and holes at the metal contact edges, which is originated from fixed charges in the ALD dielectric.

Keywords

Schottky barriers; atomic layer deposition; elemental semiconductors; hole mobility; transistors; 2D layered structures; ALD dielectric; Al₂O₃; Schottky barrier heights; atomic layer deposition; dielectric capping; few-layer phosphorene transistors; hole mobility; mechanically exfoliated few-layer phosphorene; metal contact edges; p-type-ambipolar; single elemental semiconductor; Aluminum oxide; Charge carrier processes; Dielectrics; Logic gates; Schottky barriers; Transistors; Phosphorene; Schottky barrier heights; atomic layer deposition; atomic layer deposition.; field-effect transistors;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2014.2323951

Filename

6823630