Structurally Driven Enhancement of Resonant Tunneling and Nanomechanical Properties in Diamond-like Carbon Superlattices.
We report nitrogen-induced enhanced electron tunnel transport and improved nanomechanical properties in band gap-modulated nitrogen doped DLC (N-DLC) quantum superlattice (QSL) structures. The electrical characteristics of such superlattice devices revealed negative differential resistance (NDR) behavior. The interpretation of these measurements is supported by 1D tight binding calculations of disordered superlattice structures (chains), which include bond alternation in sp(3)-hybridized regions. Tandem theoretical and experimental analysis shows improved tunnel transport, which can be ascribed to nitrogen-driven structural modification of the N-DLC QSL structures, especially the increased sp(2) clustering that provides additional conduction paths throughout the network. The introduction of nitrogen also improved the nanomechanical properties, resulting in enhanced elastic recovery, hardness, and elastic modulus, which is unusual but is most likely due to the onset of cross-linking of the network. Moreover, the materials' stress of N-DLC QSL structures was reduced with the nitrogen doping. In general, the combination of enhanced electron tunnel transport and nanomechanical properties in N-DLC QSL structures/devices can open a platform for the development of a new class of cost-effective and mechanically robust advanced electronic devices for a wide range of applications.
Department of Electrical and Computer Engineering, National University of Singapore , Singapore 117583, Singapore.|CSIR-National Physical Laboratory , K.S. Krishnan Road, New Delhi 110012, India.|Department of Physics, Indian Institute of Technology Delhi , New Delhi 110016, India.
Neeraj
N
Dwivedi
Nano-Scale Transport Physics Laboratory, School of Physics, and Centre of Excellence in Strong Materials, University of the Witwatersrand , Private Bag 3, WITS 2050 Johannesburg, South Africa.
Ross
R
McIntosh
CSIR-National Physical Laboratory , K.S. Krishnan Road, New Delhi 110012, India.|Singapore Eye Research Institute , Singapore 169856, Singapore.
Chetna
C
Dhand
CSIR-National Physical Laboratory , K.S. Krishnan Road, New Delhi 110012, India.
Sushil
S
Kumar
Department of Physics, Indian Institute of Technology Delhi , New Delhi 110016, India.
Hitendra K
HK
Malik
Nano-Scale Transport Physics Laboratory, School of Physics, and Centre of Excellence in Strong Materials, University of the Witwatersrand , Private Bag 3, WITS 2050 Johannesburg, South Africa.
Somnath
S
Bhattacharyya
carbon; elastic recovery; hardness; resonant tunneling; superlattice