Photosensitive Complementary Inverters Composed of n‐Channel ReS₂ and p‐Channel Single‐Walled Carbon Nanotube Field‐Effect Transistors

Abstract

With a surge of necessity on versatile Internet of Things (IoTs) sensors for the upcoming era of trillion sensors, [1-4] security and low-power consumption issues are key aspects among the various figures-of-merit which are required for emerging IoT sensor systems built with a variety of sensors such as photodetectors, gyroscopes, gas sensors, temperature sensors, and others. In a recent past, among a variety of sensors developed, one of the predominant research activities has been focused on the development of energy-efficient photodetectors with high level of security due to high demand for the application of highresolution image sensors, which are essentially required to be built in mobile gadgets including smart phones, car navigators,

Enhancement of Photodetective Properties on Multilayered MoS2 Thin Film Transistors via Self-Assembled Poly-L-Lysine Treatment and Their Potential Application in Optical Sensors

“…In addition, as a circuit level photodetector, photosensitive inverters were implemented and compared using a-Si:H and m-MoS 2 TFTs in Figure 5 . These photoinverters are key component of light-to-frequency conversion circuits (LFCs), which are practically beneficial for the future IoT systems required for a high level of security [ 37 , 38 , 39 , 42 ]. To demonstrate the capabilities of a-Si:H and m-MoS 2 TFTs in a circuit-level photodetector, the photo response of depletion load enhancement driver (DLED) inverters was measured.…”

Progress in light-to-frequency conversion circuits based on low dimensional semiconductors

“…In typical, photosensitive inverters were implemented via the adoption of either light shielding layers or high energy bandgap layers (~ GaN FETs) which play a role as light-insensitive driver components in the photosensitive inverter schemes [94]. In this perspective, exciton generation associated with strong binding energy in the 1D CNTs would lead to infinitesimal generation of free carriers in the channel of SWNT TFTs, and thereby, photoinsensitive behaviors are observed in the channel [81]. This is one of key opportunities for SWNT TFTs in terms of implementation of photosensitive ROs and their future opportunities in the scalable circuits for carbon nanotube transistors and their circuits.…”

“…This has important consequences for photodetectors because large enough electric fields should be provided to dissociate the exciton in photoconductive or photovoltaic devices. Thus, the afore-mentioned properties were utilized in the reverse engineering mode, which is compulsory to prohibit photocurrent generation for the application [81]. For one of examples, electrical switching properties in the 3 terminal mode should be met for specific application with the fulfilment of 3 terminal based switching action including photo-insensitivity.…”

“…Therefore, as one of the embodiments for photosensitive devices via the adoption of low dimensional semiconductors, depletion-load based photosensitive inverters, composed of light-sensitive multilayered molybdenum disulfides (m-MoS2) thin film transistors (TFTs) and visible light-insensitive gallium nitride (GaN) field-effect transistors (FETs) (or light-shielded MoS2 TFTs), were reported, which demonstrated the improved properties in terms of enlargement of detective spectrum of wavelength via layer thickness dependent energy bandgap modulation [93,94]. However, when it comes to depletion mode LFCs, power consumption issue was problematic, and thus, complementary photosensitive inverters, comprised of light-insensitive multilayered MoTe2 (m-MoTe2) (or SWNT) TFTs and light-sensitive m-MoS2 (or multilayered ReS2 (m-ReS2)) TFTs, were proposed and their feasibility for LFC schemes was confirmed [81,95]. Nevertheless, the previously reported approaches were only based on the photosensitive inverter level demonstration, and their oscillation frequency (fosc) modulation was only confirmed by simulation basis due to limited device scalability of 2D materials in the literature.…”

Flexible Light‐to‐Frequency Conversion Circuits Built with Si‐Based Frequency‐to‐Digital Converters via Complementary Photosensitive Ring Oscillators with p‐Type SWNT and n‐Type a‐IGZO Thin Film Transistors

“…[13,14] However, when it comes to depletion mode LFCs, power consumption issue has been problematic, and thus, complementary photosensitive inverters, comprised of light-insensitive molybdenum ditelluride (MoTe 2 ) (or single walled carbon nanotube (SWNT)) FETs and light sensitive MoS 2 (or Rhenium disulfide (ReS 2 )) FETs, were proposed and their feasibility for LFC schemes were confirmed. [15,16] Nevertheless, the previously reported approaches were only based on the photosensitive inverter level demonstration, and their oscillation frequency (f osc ) modulation was only confirmed by simulation basis due to limited device scalability of 2D materials in the literature.…”