Terahertz harvesting with shape-optimized InAlAs/InGaAs self-switching nanodiodes

Abstract

In this letter, self-switching nanochannels have been proposed as an enabling technology for energy gathering in the terahertz (THz) regime. Such devices combine their diode-like behavior and high-speed of operation in order to generate DC electrical power from high-frequency signals. By using finite-element simulations, we have improved the sensitivity of L-shaped and V-shaped nanochannels based on InAlAs/InGaAs samples. Since those devices combine geometrical effects with their rectifying properties at zero-bias, we have improved their performance by optimizing their shape. Results show nominal sensitivities at zero-bias in the order of 40 V−1 and 20 V−1, attractive values for harvesting applications with square-law rectifiers.

Semiconductor Surface State Engineering for THz Nanodevices

“…The key to understand the DC performance of the SSD lies on the modulation of the n ss inside the N S by the built-in electric field, producing a modification in the D L along the nanochannel. In this way, some authors indicate that the SSD can be understood as a two-dimensional field-effect transistor with gate and drain short circuited where flanges act as a double lateral-gate terminal [28,33]. The principal mechanism that controls the carrier transport of the SSD is explained in terms of the free carriers that can participate in conduction phenomena and travel through the nanochannel [22].…”

“…For short D L length, low bias is required to turn the SSD on; nevertheless, an important leakage current is present. By modulating the dimensions of the depletion region inside the nanochannel, the L-shape SSDs are found to be suitable for detection of very weak signals, making the SSD concept an important tool in the development of high-frequency integrated circuits since it has been demonstrated that by choosing appropriate geometrical dimensions, the rectification efficiency can be optimized [33,34].…”

“…It was found that W V in the range of 5-50 nm did not affect the I-V performance of the SSD and consequentially the γ 0 is constant for these modifications and being reduced with W V > 50 nm. On the other hand, small changes in W H affected strongly the DC performance of the SSD; meanwhile variation of W H from 5 to 30 nm resulted in a variation of V TH from 0 to 0.2 V [33,34], and γ 0 is optimized for W H = 30 nm. The effect of W V and W H trenches is seen in Figure 9(a).…”

“…This reduction in the nanochannel resistance is translated into a reduction in the γ 0 of ~25% as it is plotted in the inset of Figure 11. Contrarily, the γ 50Ω exhibits a modification from 4 × 10 −3 for a single base SSD to 63 × 10 −3 V −1 for a 16 array-based SSD [33]. It is clear that the major quantity of SSD in parallel results in the reduction of the device resistance, which improves the impedance matching between rectifier elements and antennas by using the appropriate number of SSD [40].…”

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

“…[ 10,23 ] For graphene and InAlAs/InGaAs SSDs, an alternate asymmetric “sawtooth” morphology has also been explored. [ 24,25 ] GDs are of particular interest because they can typically rectify up to THz frequencies and are thus relevant to the development of long‐wavelength energy harvesting, THz imaging sensors, and high‐speed signal processing technologies. [ 26 ]…”