Graphene-Assisted Electrostatic Screening of Resonant Transport in MR-DWELL Dosimeters with Tunable Sensitivity--Radiation Tolerance Trade-off: A Reduced-Order Benchmark and Self-Consistent Perspective

Abstract

We propose a Multi-Resonant Double-barrier Quantum-dot-in-a-Well (MR-DWELL) dosimeter with a tunable trade-off between sensitivity and radiation tolerance, realized through graphene-assisted electrostatic screening. The sensing mechanism relies on radiation-induced trapped charge that shifts and broadens resonant tunneling states in the DWELL heterostructure. The~dimensionless capacitance ratio $\eta =C_Q/C_{\mathrm{geo}}$ is introduced as the universal design parameter: it~controls the screening factor $S=\eta /(1+\eta )$ and thereby the trade-off between sensitivity and radiation hardness. For $\eta =2.09$ the effective low-dose shift coefficient is reduced threefold (from $0.14$~to $0.045meV/mGy$), while the screened architecture retains $\sim 83\%$ of the peak tunneling current and a peak-to-valley ratio $\sim 10$ after $1\mathrm{MGy}$, thereby preserving the dosimetric sensitivity required for practical readout. The~second-derivative spectroscopy $d^{2}I/d{V}^2$ is identified as a robust experimental readout. A~reduced-order Landauer model calibrated against literature data is employed for the screening physics, while a self-consistent NEGF-Poisson-trap framework is formulated for future quantitative validation. Explicit design rules for three operating regimes (high sensitivity, balanced, maximum hardness) are provided, together with a three-population trap model that conceptually enables dose-rate discrimination in the FLASH radiotherapy regime. A~comparative analysis of model vintages and their methodological foundations is included to guide interpretation of numerical predictions.

arXiv commentv3: The manuscript has been substantially revised to make the model and its limitations clear. Numerical values were corrected, the different model versions were compared, and recent studies on radiation hardness and FLASH dosimetry were added. The title now emphasizes the key idea: balancing sensitivity with radiation tolerance. 13 pages, 10 figures