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Ma Y, Shen C, Zhang A, Chen L, Liu Y, Chen J, Liu Q, Li Z, Amer MR, Nilges T, Abbas AN, Zhou C. Black Phosphorus Field-Effect Transistors with Work Function Tunable Contacts. ACS NANO 2017; 11:7126-7133. [PMID: 28653827 DOI: 10.1021/acsnano.7b02858] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Black phosphorus (BP) has been recently rediscovered as an elemental two-dimensional (2D) material that shows promising results for next generation electronics and optoelectronics because of its intrinsically superior carrier mobility and small direct band gap. In various 2D field-effect transistors (FETs), the choice of metal contacts is vital to the device performance, and it is a major challenge to reach ultralow contact resistances for highly scaled 2D FETs. Here, we experimentally show the effect of a work function tunable metal contact on the device performance of BP FETs. Using palladium (Pd) as the contact material, we employed the reaction between Pd and H2 to form a Pd-H alloy that effectively increased the work function of Pd and reduced the Schottky barrier height (ΦB) in a BP FET. When the Pd-contacted BP FET was exposed to 5% hydrogen concentrated Ar, the contact resistance (Rc) improved between the Pd electrodes and BP from ∼7.10 to ∼1.05 Ω·mm, surpassing all previously reported contact resistances in the literature for BP FETs. Additionally, with exposure to 5% hydrogen, the transconductance of the Pd-contacted BP FET was doubled. The results shown in this study illustrate the significance of choosing the right contact material for high-performance BP FETs in order to realize the real prospect of BP in electronic applications.
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Affiliation(s)
- Yuqiang Ma
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Chenfei Shen
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Anyi Zhang
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Liang Chen
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Yihang Liu
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Jihan Chen
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Qingzhou Liu
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Zhen Li
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
| | - Moh R Amer
- Center of Excellence for Green Nanotechnologies, Joint Centers of Excellence Program, King Abdulaziz City for Science and Technology , P.O Box 6086, Riyadh 11442, Saudi Arabia
- Department of Electrical Engineering, University of California, Los Angeles , 420 Westwood Plaza, 5412 Boelter Hall, Los Angeles, California 90095, United States
| | - Tom Nilges
- Department für Chemie, Technische Universität München , Lichtenbergstrasse 4, 85747 Garching b. München, Germany
| | - Ahmad N Abbas
- Center of Excellence for Green Nanotechnologies, Joint Centers of Excellence Program, King Abdulaziz City for Science and Technology , P.O Box 6086, Riyadh 11442, Saudi Arabia
- Department of Electrical and Computer Engineering, University of Jeddah , Dhahban 23881, Saudi Arabia
- Department of Electrical and Computer Engineering, King Abdulaziz University , Abdullah Sulayman Street, Jeddah 22254, Saudi Arabia
| | - Chongwu Zhou
- Department of Electrical Engineering, University of Southern California , 3710 McClintock Avenue, Los Angeles, California 90089-0271, United States
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