1
Return

In-Substrate Imaging of Diamond–hBN FET Current via Wide-Field Quantum Diamond Microscopy

delete2026-06-11
delete0
PRE
AI
A
Anuj Bathla
S
Subrat Kumar Pradhan
A
Ajit Kumar Dash
P
Prabhat Anand
M
M. Girish Chandra
K
Kenji Watanabe
T
Takashi Taniguchi
A
Akshay Singh
V
Veeresh Deshpande
K
Kasturi Saha *
DOI:10.1021/acsaelm.6c00194delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
We demonstrate wide-field magnetic imaging of current flow in hydrogen-terminated diamond field-effect transistors (FETs) through in-substrate nitrogen-vacancy (NV) centers. Hydrogen termination of the diamond surface induces a two-dimensional hole gas (2DHG), while an ensemble of near-surface NV centers located ∼1 μm below the surface enables operando magnetic imaging of current flow with micrometer-scale spatial resolution. The FETs were electrically characterized over a range of drain–source biases, Vds = 0 to −15 V, and gate voltages, Vgs = +3 to −9 V, followed by in situ wide-field NV magnetometry during device operation. Magnetic field maps and reconstructed current-density distributions directly visualize current injection at the source–drain contacts and transport beneath the hBN-gated channel. Magnetic field maps reveal current-density variations in the channel region owing to non-uniformities or defects in the gate dielectric. In addition, we observe a pronounced enhancement of the drain current (∼600 to 900 μA) and a shift in the apparent threshold voltage during laser illumination, reflecting photo-induced changes in channel electrostatics. By correlating gate-dependent magnetic images with simultaneous electrical measurements, we directly link spatial current distributions to FET transfer characteristics, providing new insight into buried interface transport and non-uniform gating effects in the transistor channel. As the methodology is compatible with top-gated FETs, it can be used to map channel current distributions with micrometer resolution in emerging channel materials, such as 2D materials and wide-bandgap channels, and establish wide-field NV magnetometry as a powerful platform for probing charge transport in transistors and van der Waals dielectric heterostructures.
Keywords:
NV magnetometry
diamond FET
hexagonal boron nitride
current density imaging
two-dimensional hole gas
wide-field magnetic imaging
quantum sensing

Journal

ACS Applied Electronic Materials cover
ACS Applied Electronic Materials
IF:
4.7
Papers:
5.0K
Citations:
1.4W

Organization

I
Indian Institute of Science
Scholars:
1.4K
Papers: 605
Citations: 1.3W
T
tata consultancy services
Scholars:
16
Papers: 12
Citations: 0
N
National Institute for Materials Science
Scholars:
599
Papers: 285
Citations: 2.2W
I
indian institute of technology bombay
Scholars:
746
Papers: 307
Citations: 0
Cited Papers

Cited Papers

Citing Papers

Citing Papers