Improved Rectification Performance and Terahertz Detection in Hybrid Structure of Self-Switching Device (SSD) and Planar Barrier Diode (PBD) Using Two-Dimensional Device Simulation

Abstract

Recently, simulations of In0.48Ga0.52As-based Planar Barrier Diode (PBD) and Self-Switching Device (SSD) as millimeter-wave rectifiers were reported. Both PBD and SSD have a planar structure, but with different insulating shapes and working principles. In this work, a hybrid structure of the reported PBD and SSD in a parallel configuration is proposed, to exploit the advantages of each device. The advantages of high rectifying properties in the SSD and fast switching rate of the PBD are combined in this hybrid structure in order to obtain an improved rectification performance at zero-bias in the near terahertz frequency region. Analysis of the curvature co-efficient, γ, which is defined as the ratio of the second order to the first order derivative of the device’s I-V function was performed to evaluate the rectification performance. AC transient analyses were then executed in various frequencies to imitate the high-frequency signal inputs. By using this hybrid structure, the highest value of γ achieved has been improved to ~19 V-1 at 70 mV, and ~6 V-1 at zero-bias (compared to the previous results on PBDs). The estimated cut-off frequency obtained was ~360 GHz (0.36 THz), operating at zero-bias.

Omega‐Gate Silicon Nanowire Geometric Diodes with Reconfigurable Self‐Switching Operation and THz Rectification

“…One difference is that maximum depletion is observed under reverse bias for the planar SSD and under zero bias for the SSGD, although the SSGD trend is consistent with “V‐shaped” SSDs [ 25 ] and planar barrier diodes. [ 51,52 ] In addition, the magnitude of depletion between the two devices differs by ≈4 orders of magnitude, as apparent by a comparison of the color bar axis limits in Figure 4A. This difference originates from the modulated dopant profile in the SSGD compared to the uniform dopant profile in the planar SSD, causing the NW SSGD to have a greater magnitude of n within the channel for carrier transport under forward bias.…”

“…One difference is that maximum depletion is observed under reverse bias for the planar SSD and under zero bias for the SSGD, although the SSGD trend is consistent with "V-shaped" SSDs [25] and planar barrier diodes. [51,52] In addition, the magnitude of depletion between the two devices differs by ≈4 orders of magnitude, as apparent by a comparison of the color bar axis limits in Figure 4A. This difference originates from the modulated dopant profile in the SSGD compared to the uniform dopant profile in the planar SSD, causing the NW SSGD to have a greater A) Electron concentration, n, under zero (V app = 0 V), forward (V app = −1 V), and reverse (V app = 1 V) biases applied to the righthand side of an n-type Si SOI SSD device [10] (left; scale bar, 1 μm) and an n-type Si NW SSGD device (right; scale bar, 150 nm) in grounding configuration 1 at V g = −0.7 V. B) Semi-logarithmic I-V curves for the NW SSGD device (yellow) corresponding to the structures in panel A and planar SSD device (black) assuming a Si thickness of 205 nm.…”