Zero‐Bias Power‐Detector Circuits based on MoS₂ Field‐Effect Transistors on Wafer‐Scale Flexible Substrates

Abstract

We demonstrate the design, fabrication, and characterization of wafer-scale, zero-bias power detectors based on two-dimensional MoS2 field effect transistors (FETs). The MoS2 FETs are fabricated using a wafer-scale process on 8 µm thick Polyimide film, which in principle serves as flexible substrate. The performances of two CVD-MoS2 sheets, grown with different processes and showing different thicknesses, are analyzed and compared from the single device fabrication and characterization steps to the circuit level. The power detector prototypes exploit the nonlinearity of the transistors above the cut-off frequency of the devices. The proposed detectors are designed employing a transistor model based on measurement results. The fabricated circuits operate in Ku-band between 12 and 18 GHz, with a demonstrated voltage responsivity of 45 V/W at 18 GHz in the case of monolayer MoS2 and 104 V/W at 16 GHz in the case of multilayer MoS2, both achieved without applied DC bias. They are the best performing power detectors fabricated on flexible substrate reported to date. The measured dynamic range exceeds 30 dB outperforming other semiconductor technologies like silicon complementary metal oxide semiconductor (CMOS) circuits and GaAs Schottky diodes.

High‐Performance Flexible MoS2 Transistors Using Au/Cr/Al/Au as Source/Drain Electrodes

“…Additionally, an assessment of the electrical performances (including on/off current ratio, R SD , and μ FE ) of flexible MoS 2 FETs with different source/drain electrodes was conducted, and the results are summarized in Table 1. [14,32,33,34,35,36,37] By employing the appropriate thickness and electrode stack structure, Al contacts can be implemented to maximize the advantageous electrical properties of flexible MoS 2 FETs (i.e., on/off current raion and R SD ). The extracted hysteresis and subthreshold slope (SS) of these devices with different contact electrodes was shown in Figure S5 (Supporting Information).…”

Two‐Dimensional Semiconductors: From Device Processing to Circuit Integration

“…[ 193 ] Several studies have investigated the use of MoS 2 transistors in RF circuit modules, including power amplifiers, mixers, and wireless amplitude‐modulated receivers. [ 186,188,194 ] Recently, a zero‐bias MoS 2 power detector circuit was demonstrated on a flexible substrate with operating at 12–18 GHz (Ku‐band) reported by Reato et al. (Figure 12c).…”

Potential of Transition Metal Dichalcogenide Transistors for Flexible Electronics Applications

“…[35] Also, analog circuits, such as operational amplifiers or power detectors have been demonstrated using MoS 2 -based NMOS FETs. [36,37] CMOS circuits often outperform NMOS and PMOS circuits significantly, especially in terms of power consumption. For that there are essentially two possibilities: combining two different TMDCs on one foil, such as MoS 2 for NMOS and WSe 2 for PMOS FETs, [33] or using one TMDC, which can operate both as NMOS and as PMOS as demonstrated using two different contact metals with appropriate work functions.…”