Hybrid Gate Dielectrics Research Articles

Highly Robust Atomic Layer Deposition‐Indium Gallium Zinc Oxide Thin‐Film Transistors with Hybrid Gate Insulator Fabricated via Two‐Step Atomic Layer Process for High‐Density Integrated All‐Oxide Vertical Complementary Metal‐Oxide‐Semiconductor Applications

Highly reliable atomic layer deposition (ALD)‐derived In‐Ga‐Zn‐O thin‐film transistors with high field‐effect mobility (μFE) and hydrogen (H) resistivity are crucial for the semiconductor industry. Herein, a hybrid Al2O3 gate insulator (GI) is proposed that is designed by controlling the plasma‐enhanced ALD and thermal ALD processes in situ to demonstrate robust characteristics. A hybrid GI is applied to the top‐gate geometry of an In0.71Ga0.08Zn0.21O active layer. The optimal device exhibits exceptional electrical characteristics, including a threshold voltage of 0.37 V, μFE of 150.7 cm2 V s−1, subthreshold swing of 64.0 mV decade−1, and hysteresis of 0.02 V. It demonstrates high resistance to H annealing and reliable positive bias temperature stress, as well as changes in VTH shifts of −0.43 and 0.00 V, respectively. The excellent electrical characteristics and high robustness of the device can be attributed to the precise control of H, oxygen, and carbon species within the upper region of the hybrid GI. The achievement of robust device characteristics enables the design of a novel vertical complementary metal‐oxide‐semiconductor inverter that exhibits a voltage gain of 44.7 V V−1 and a noise margin of 87.5% at a 10 V supply voltage.

Optimization of Polyelectrolyte and Polymers in Inorganic/Organic Hybrid Gate Dielectrics for Flexible OFETs

Optimization of Polyelectrolyte and Polymers in Inorganic/Organic Hybrid Gate Dielectrics for Flexible OFETs

Organic field-effect transistors with low-temperature curable high-k hybrid gate dielectrics

We report a low-voltage-operated organic field-effect transistor that uses a hybrid gate insulator that has a high dielectric constant k. The gate insulator consists of a high-k polymer cyanoetylated pullulan (CEP) that can be efficiently cross-linked by glycidoxypropyltrimethoxysilane (GOPTMS) at low temperature (∼110 °C). The very low curing temperature is below the glass transition temperature T g of conventional plastic substrates for plastic electronics, and is therefore compatible with many plastic substrates for plastic electronics. The cross-linking is very efficient in that only 1/10 (w:w) GOPTMS: CEP produced densely cross-linked thin films with a smooth surface, good insulating property, high capacitance density and high k. The devices functioned at low voltage, and exhibited charge carrier mobility ∼1.83 cm2 V−1 s−1, and steep substheshold swing ∼88 mV dec−1. These results imply that high quality polymer gate insulators are achievable at low temperature with a very small fraction of blended crosslinking agents; this characteristic offers a method to achieve portable all-plastic flexible electronics that function at low voltage.

Mechanically Durable Organic/High-k Inorganic Hybrid Gate Dielectrics Enabled by Plasma-Polymerization of PTFE for Flexible Electronics.

To achieve both the synergistic advantages of outstanding flexibility in organic dielectrics and remarkable dielectric/insulating properties in inorganic dielectrics, a plasma-polymerized hafnium oxide (HfOx) hybrid (PPH-hybrid) dielectric is proposed. Using a radio-frequency magnetron cosputtering process, the high-k HfOx dielectric is plasma-polymerized with polytetrafluoroethylene (PTFE), which is a flexible, thermally stable, and hydrophobic fluoropolymer dielectric. The PPH-hybrid dielectric with a high dielectric constant of 14.17 exhibits excellent flexibility, maintaining a leakage current density of ∼10-8 A/cm2 even after repetitive bending stress (up to 10000 bending cycles with a radius of 2 mm), whereas the HfOx dielectric degrades to be leaky. To evaluate its practical applicability to flexible thin-film transistors (TFTs), the PPH-hybrid dielectric is applied to amorphous indium-gallium-zinc oxide (IGZO) TFTs as a gate dielectric. Consequently, the PPH-hybrid dielectric-based IGZO TFTs exhibit stable electrical performance under the same harsh bending cycles: a field-effect mobility of 16.99 cm2/(V s), an on/off current ratio of 1.15 × 108, a subthreshold swing of 0.35 V/dec, and a threshold voltage of 0.96 V (averaged in nine devices). Moreover, the PPH-hybrid dielectric-based IGZO TFTs exhibit a reduced I-V hysteresis and an enhanced positive bias stress stability, with the threshold voltage shift decreasing from 4.99 to 1.74 V, due to fluorine incorporation. These results demonstrate that PTFE improves both the mechanical durability and electrical stability, indicating that the PPH-hybrid dielectric is a promising candidate for high-performance and low-power flexible electronics.

Organic-Inorganic Hybrid Gate Dielectrics Using Self-Assembled Multilayers For Low-Voltage Operating Thin-Film Transistors

Advanced electronic materials have attracted great interest for their potential use in flexible, large-area, and printable electronic applications. However, fabricating high-performance low-voltage thin-film transistors (TFTs) for those applications with these advanced semiconductors is still challenging because of a lack of dielectric materials which satisfy both the required electrical and physical performance. In this work, we report self-assembled hybrid multilayer gate dielectrics prepared using a facile solution procedure to achieve organic semiconductor and amorphous oxide semiconductor-based thin-film transistors with ultralow operating voltage. These self-assembled hybrid multilayer gate dielectrics were constructed by iterative self-assembly of synthesized bifunctional phosphonic acid-based organic molecules and ultrathin high-k hafnium oxide layers. The novel self-assembled hybrid multilayer gate dielectrics exhibit excellent dielectric properties with exceptionally large capacitances (up to 815 nF/ cm2) and low-level leakage current densities of < 1.56 × 10-6 A/cm2, featureless morphology (RMS roughness < 0.24 nm), and thermal stability (up to 300 °C). Consequently, these hybrid gate dielectrics can be incorporated into thin-film transistors with pentacene as p-type organic semiconductors, and with indium oxide as n-type inorganic semiconductors. The resulting TFTs functioned at ultralow voltages (< ± 2 V) and achieved high transistor performances (hole mobility: 0.88 cm2 / V·s, electron mobility: 7.8 cm2 / V·s and on/off current ratio >104, and threshold voltage: ± 0.5 V).

Performance enhancement of p-type organic thin-film transistors by surface modification of hybrid dielectrics

The quality of the dielectric/organic semiconductor interface is a critical issue, because it determines the charge transport properties in organic thin-film transistors (OTFTs). High- k organic-inorganic hybrid films have received considerable attention for their outstanding dielectric properties, including low leakage currents, high breakdown fields, and suitable band offsets against the organic semiconductor. However, Hf and Zr hybrid gate dielectrics on p-type OTFTs show poor charge transport properties in the organic semiconductor channel, due to the polaron disorder elicited by the high- k properties and the presence of the –N(CH 3 ) 2 polarity (hole trapper) on the dielectric/semiconductor interface. In this report, the surface of the Hf and Zr hybrid dielectrics was capped by an ultra-thin poly-1,3,5-trivinyl-1,3,5,-trimethyl-cyclosiloxane (pV3D3) layer formed via an initiated chemical vapor deposition (iCVD) process, to modify the hybrid dielectrics/semiconductor interface. The pV3D3-capped Hf and Zr hybrid OTFTs show an enhanced V T stability while a large amount of V T shift was observed from the Hf and Zr hybrid OTFTs. This large amount of V T shift is attributed to the hole trap sites originated by –N(CH 3 ) 2 on the uncapped hybrid dielectrics. Furthermore, the p-type OTFTs with the pV3D3-capped hybrid dielectrics show a higher mobility than those with the uncapped hybrid dielectrics. The presence of the non-polar/low- k pV3D3 on the hybrids contribute to narrow the density of state (DOS) in the organic channel, improving the charge transport properties. This combined approach using the bulk layer of Hf and Zr hybrid films and the pV3D3 capping layer can overcome the limitations of single-layer hybrid dielectrics and improve the overall device performance of the OTFTs. • Performance Enhancement of p-type OTFTs through simple surface modification. • Ultra-thin (~1 nm) non-polar low-k dielectric on the hybrid. • Simple process to change the surface properties. • Systematic investigation of interface quality which affect charge transport in organic semiconductor.

Organic–inorganic hybrid gate dielectric using bifunctional polyhedral oligomeric silsesquioxane for low‐voltage organic thin‐film transistors

AbstractHerein, we report the facile fabrication of rationally designed, high‐performance organic–inorganic hybrid dielectric films constructed by combining a one‐step solution processing and ultraviolet (UV) irradiation under ambient conditions. For the exceptional dielectric properties and facile fabrication process, we use bifunctional polyhedral oligomeric silsesquioxane (POSS) with UV cross‐linking and hydrophobic properties to prepare precursor solutions for the hybrid dielectric films. The bifunctional POSS enables the fabrication of a dense network of hybrid films with UV curing at under ambient conditions. The prepared hybrid gate dielectrics exhibit high capacitance (~300 nF/cm2), exceptional surface smoothness (root‐mean‐square roughness <0.4 nm), and excellent leakage current properties (10−6 A/cm2 at 2 MV/cm). In addition, the hydrophobic function of bifunctional POSS enables the low surface energy of fabricated hybrid gate dielectrics without further treatment. Pentacene‐based organic thin‐film transistors, fabricated with a hybrid dielectric, function well at low voltage with excellent thin‐film transistor performances.

Facile Synthesis of Solution-Processed Silica and Polyvinyl Phenol Hybrid Dielectric for Flexible Organic Transistors.

A high-quality dielectric layer is essential for organic thin-film transistors (OTFTs) operated at a low-power consumption level. In this study, a facile improved technique for the synthesis of solution-processed silica is proposed. By optimizing the synthesis and processing technique fewer pores were found on the surface of the film, particularly no large holes were observable after improving the annealing process, and the improved solution–gelation (sol–gel) SiOx dielectric achieved a higher breakdown strength (1.6 MV/cm) and lower leakage current density (10−8 A/cm2 at 1.5 MV/cm). Consequently, a pentacene based OTFT with a high field effect mobility (~1.8 cm2/Vs), a low threshold voltage (−1.7 V), a steeper subthreshold slope (~0.4 V/dec) and a relatively high on/off ratio (~105) was fabricated by applying a hybrid gate insulator which consisted of improved sol–gel SiOx and polyvinyl phenol (PVP). This could be ascribed to both the high k of SiOx and the smoother, hydrophobic dielectric surface with low trap density, which was proved by atomic force microscopy (AFM) and a water contact angle test, respectively. Additionally, we systematically studied and evaluated the stability of devices in the compressed state. The devices based on dielectric fabricated by conventional sol–gel processes were more susceptible to the curvature. While the improved device presented an excellent mechanic strength, it could still function at the higher bending compression without a significant degradation in performance. Thus, this solution-process technology provides an effective approach to fabricate high-quality dielectric and offers great potential for low-cost, fast and portable organic electronic applications.

Enhanced Optical Switching Characteristics of Organic Phototransistor by Adopting Photo-Responsive Polymer in Hybrid Gate-Insulator Configuration.

In this study, we developed polymer gate insulator-based organic phototransistors (p-OPTs) with improved optical switching properties by using a hybrid gate insulator configuration. The hybrid gate insulator of our p-OPT has a photoresponsive layer made of poly(4-vinylphenol) (PVP), which enhances the photoresponse, and an interfacial layer of poly(methyl methacrylate) for reliable optical switching of the device. Our hybrid gate insulator-equipped p-OPT exhibits well-defined optical switching characteristics because no specific type of charge is significantly trapped at an interfacial layer/organic semiconductor (OSC) interface. Moreover, our device is more photoresponsive than the conventional p-OPT (here, an OPT with a single-polymer poly(methyl methacrylate) (PMMA) gate insulator), because the characteristic ultraviolet (UV) absorption of the PVP polymer allows the photoresponsive layer and OSC to contribute to the generation of charge carriers when exposed to UV light.

High Performance Amorphous In–Ga–Zn–O Thin-Film Transistors with Low Temperature High-k Solution Processed Hybrid Gate Insulator

For flexible display applications, high performance amorphous In–Ga–Zn–O (a-IGZO) thin-film transistors (TFTs) fabricated by low temperature process are required. Moreover, high dielectric constant (high-k) material which enables higher mobility and lower threshold voltage while minimizing the device size are excellent candidates to replace SiO2 gate insulators in conventional oxide semiconductor TFTs. Therefore, nanocomposite material containing high-k BaTiO3 nanoparticles and transparent poly-siloxane (PSX) hybrid polymer were deposited as gate insulator in a-IGZO TFTs to facilitate the reduction of process temperature due to the high temperature requirement (>650 ºC) of BaTiO3. This paper presents the performance and analysis of a-IGZO TFTs with high-hybrid gate insulators at different ratios of BaTiO3/PSX deposited by solution process at a lower temperature (300 ºC). The TFT shows a high mobility of 35.59 cm2 V−1 s−1, low threshold voltage of 0.4 V, and gate leakage current of ∼10−10 A.

Network Structure Modification‐Enabled Hybrid Polymer Dielectric Film with Zirconia for the Stretchable Transistor Applications

AbstractStretchable electronic devices should be enabled by the smart design of materials and architectures because their commercialization is limited by the tradeoff between stretchability and electrical performance limits. In this study, thin‐film transistors are fabricated using strategies that combine the unit process of a novel hybrid gate insulator and low‐temperature indium gallium tin oxide (IGTO) channel layer and a stress‐relief substrate structure. Novel hybrid dielectric films are synthesized and their molecular structural configurations are analyzed. These films consist of a polymer [poly(4‐vinylphenol‐co‐methylmethacrylate)], cross‐linkers having different binding structures [1,6‐bis(trimethoxysilyl)hexane (BTMSH), dodecyltrimethoxysilane, and poly(melamine‐co‐formaldehyde)], and an inorganic zirconia component (ZrOx). The hybrid film with BTMSH cross‐linker and 0.2 M ZrOx exhibits excellent insulating properties as well as mechanical stretchability. IGTO transistors fabricated on polyimide‐coated glass substrates are transferred to the rubber substrate to offer stretchability of the transistor pixelated thin‐film transistors. IGTO transistors fabricated on stretchable substrates using these strategies show promising electrical performance and mechanical durability. After 200 stretchability test cycles under uniaxial elongation of approximately 300%, the IGTO transistor still retains a high carrier mobility of 21.7 cm2 V−1 s−1, a low sub‐threshold gate swing of 0.68 V decade−1 and a high ION/OFF ratio of 2.0 × 107.

Organic Thin‐Film Transistors Fabricated by Solution‐Processed and Low‐Temperature Condensed Hybrid Gate Dielectrics

Herein, we report on the preparation of new solution‐processed and low‐temperature condensed organic–inorganic hybrid dielectric films and their electrical properties for applications in low‐power organic thin‐film transistors (OTFTs). The low‐temperature condensed hybrid dielectric films (~19 nm thick) were simply fabricated by spin coating a mixture solution of a zirconium chloride and synthesized bifunctional phosphonic acid organic reagents, followed by annealing at a relatively low temperature (~90 °C). The prepared hybrid dielectric films exhibited excellent dielectric properties (low leakage current density < 10−6 A/cm2 and high capacitance of 520 nF/cm2) as well as a smooth surface (RMS roughness <0.3 nm). Consequently, the pentacene‐based OTFTs were fabricated using these hybrid dielectrics and functioned effectively at a relatively low operating bias (−2 V) and exhibited great TFT characteristics (hole mobility: 0.3 cm2/V/s, low threshold voltage: −0.7 V, low subthreshold swing: 0.17 V/dec, on/off current ratio: 105).

Low-Temperature Deposition of Inorganic–Organic HfO2–PMMA Hybrid Gate Dielectric Layers for High-Mobility ZnO Thin-Film Transistors

Low-temperature solution-processed inorganic–organic hybrid gate dielectrics are considered as emerging candidates for future low-cost flexible electronic devices, which are alternatives to high-temperature inorganic-based gate dielectric materials. In the present work, we developed a novel inorganic–organic HfO2–PMMA hybrid dielectric material by an efficient eco-friendly sol–gel method, deposited by spin-coating technique and converted into dielectric thin films at a very low thermal annealing temperature of 185 °C. The HfO2–PMMA hybrid thin-film formation was systematically investigated by FTIR and XPS techniques. Subsequently, a very low surface roughness of 0.8 nm and high uniformity of hybrid thin films were observed by tapping-mode AFM. Also, the thin films showed a hydrophilic nature with a high surface energy of 59.9 mJ/m2 as observed by the contact angle technique. The insulating properties of this hybrid film, studied by C–V and I–V measurements, showed very low leakage current density under 1 ...

Stretchable Polymer Gate Dielectric by Ultraviolet-Assisted Hafnium Oxide Doping at Low Temperature for High-Performance Indium Gallium Tin Oxide Transistors.

This paper reports the fabrication of indium gallium tin oxide (IGTO) thin-film transistors (TFTs) with ultraviolet (UV)-treated PVP- co-PMMA-based hybrid gate insulators at an extremely low temperature (≤150 °C). Synergetic hafnia loading and UV treatment were used to tailor the mechanical softness and hydroxyl fraction in the polymer dielectric film. The UV-treated hybrid dielectric film had a low hydroxyl concentration, a smoother surface, and a denser packing nature, which can be explained by the high ionicity of hafnium oxide and photon-assisted improvement in the cohesion between organic and inorganic materials. Suitability of the UV-treated hybrid dielectric film as a gate insulator was evaluated by fabricating bottom gate TFTs with sputtered IGTO films as a channel layer, which showed high carrier mobility at a low temperature. The resulting IGTO TFTs with a UV-treated hybrid gate insulator exhibited a remarkable high field-effect mobility of 25.9 cm2/(V s), a threshold voltage of -0.2 V, a subthreshold gate swing of 0.4 V/decade, and an ION/OFF ratio of >107 even at a low annealing temperature of 150 °C. The fabricated IGTO TFTs with the UV-treated hybrid dielectric film on the plastic substrate were shown to withstand the 100 times mechanical bending stress even under an extremely small curvature radius of 1 mm due to the intrinsic stretchability of the hybrid dielectric film.

Hybrid gate dielectrics: a comparative study between polyvinyl alcohol/ $$\hbox {SiO}_{2}$$ SiO 2 nanocomposite and pure polyvinyl alcohol thin-film transistors

Polyvinyl alcohol (PVA) thin films as polymer gate dielectrics, with and without \(\hbox {SiO}_{2}\) nanoparticles were fabricated using spin-coating. Surface roughness and hydrophilicity of PVA and PVA/\(\hbox {SiO}_{2}\) thin films were studied by contact-angle measurements and atomic force microscopy. The dielectric properties were characterized via capacitance and leakage-current measurements on metal–insulator–metal structures. In order to further investigate the application potential of such materials as a replacement for conventional inorganic dielectrics such as \(\hbox {SiO}_{2}\) in organic thin-film transistors, devices were fabricated based on these polymers using \(\upalpha \), \(\upomega \)-dihexylquaterthiophene as an active layer. Performance of the devices was realized by electrical measurements and Kelvin probe force microscopy. All transistors showed hole and electron mobilities in the low-voltage range. PVA/\(\hbox {SiO}_{2}\) films showed larger capacitance, less hydrophilicity, rougher surfaces and considerable leakage currents compared with those with neat PVA. Although integrating nanoparticles modified surface electronic properties and showed a shift in surface potential as observed in Kelvin probe force measurements, it appears that non-polymeric and neat polymeric dielectric materials could still be a privilege to nanocomposite polymeric dielectrics for optoelectronic applications.

Solution-processed organic-inorganic hybrid gate insulator for complementary thin film transistor logic circuits

In this work, we demonstrated a poly(4-vinylphenol-co-methyl methacrylate) (PVP-co-PMMA)/Al2O3 double-stacked insulator deposited by solution process. The double-stacked insulator exhibited higher degree of performance uniformity than individual single-stacked insulators. We fabricated an inverter circuit in order to demonstrate the applicability of the proposed insulator in complementary logic circuits, which are composed of metal oxide thin film transistors as the n-channel device and organic thin film transistors as the p-channel device. We utilized amorphous indium gallium zinc oxide thin film transistor and pentacene thin film transistor for the n-channel and p-channel devices, respectively. It was observed that the PVP-co-PMMA/Al2O3 double-stacked insulator had the effect of overcoming the problems related to individual single-stacked layers, such as high leakage current of Al2O3 and low dielectric constant of PVP-co-PMMA. The inverter operated at a threshold voltage of 1.5 V and exhibited high voltage gain of 17.3 V/V at the supply voltage of 3 V.

Room-temperature solution-processed, ZrOx-based hybrid gate dielectrics for low-voltage organic thin-film transistors on plastic substrates

For advanced electronic device applications including printable, flexible organic electronics and bioelectronics, it is crucial to develop novel dielectric materials with high dielectric strength and low-temperature processability compatible with plastic substrates for producing flexible and low-voltage organic thin-film transistors (OTFTs). Herein, we report the facile fabrication of rationally designed, high-capacitance hybrid gate dielectric films for low-voltage OTFTs on plastic substrates via a room-temperature solution process. To create room-temperature-processed gate dielectrics with high dielectric strength, we designed organic-inorganic hybrid gate dielectric films by including ZrOx networks as inorganic high-k oxide materials for obtaining large capacitance and 1,6-hexanediol diacrylate as a bifunctional UV cross-linking agent and a flexible organic component for increasing the density and flexibility of films and ensuring room-temperature processability. The UV cross-linked ZrOx-based hybrid composite films with a 15 nm thickness showed excellent dielectric properties with a leakage current density of ∼10−6 A/cm2 and a capacitance of 640 nF/cm2. The film surfaces were modified with hydrophobic self-assembled monolayers to match the surface energy of organic semiconductors for enhancing the OTFT performance. The utility of the hybrid dielectrics for flexible OTFTs was demonstrated by realizing pentacene TFTs on plastic substrates with a low operating voltage at –2.5 V, a high on/off current ratio of 105, a threshold voltage as low as –0.7 V, and a hole mobility up to 0.47 cm2 V−1 s−1, which are comparable to those performed on Si substrates.

Photocrosslinkable zinc diacrylate-based gate insulators for reliable operation of organic thin film transistors

Abstract We report new organic-inorganic hybrid gate insulator materials containing solution-processable zinc diacrylate (ZnDA) and dipentaerythritol penta-/hexa-acrylate (DPHA) to fabricate high-performance and reliable organic thin film transistors (OTFTs). ZnDA-DPHA organic-inorganic hybrid materials can be crosslinked by ultraviolet illumination (λmax = 365 nm) within 7 min in the presence of a photoinitiator. Hence, the crosslinked insulator film provides not only good insulating properties (such as a dielectric constant of ca. 4.95 and low leakage current of

A Hybrid Gate Dielectrics of Ion Gel with Ultra-Thin Passivation Layer for High-Performance Transistors Based on Two-Dimensional Semiconductor Channels

We propose a hybrid gate structure for ion gel dielectrics using an ultra-thin Al2O3 passivation layer for realizing high-performance devices based on electric-double-layer capacitors. Electric-double-layer transistors can be applied to practical devices with flexibility and transparency as well as research on the fundamental physical properties of channel materials; however, they suffer from inherent unwanted leakage currents between electrodes, especially for channel materials with low off-currents. Therefore, the Al2O3 passivation layer was introduced between the metal electrodes and ion gel film as a leakage current barrier; this simple approach effectively reduced the leakage current without capacitance degradation. In addition, we confirmed that a monolayer MoS2 transistor fabricated with the proposed hybrid gate dielectric exhibited remarkably enhanced device properties compared to a transistor using a normal ion gel gate dielectric. Our findings on a simple method to improve the leakage current properties of ion gels could be applied extensively to realize high-performance electric-double-layer transistors utilizing various channel materials.

Dual-Gate Phototransistor With Perovskite Quantum Dots-PMMA Photosensing Nanocomposite Insulator

Dual-gate InGaZnO thin-film-transistors were fabricated to demonstrate their feasibility as phototransistors by fully exploiting the perovskite quantum dots (QDs) with superior quantum yield. Here, we show that by coupling the top-gate photo sensing polymethyl methacrylate (PMMA)/CsPbBr3 QDs hybrid insulator with the classic SiO2 bottom-gate insulator, the phototransistor can exhibit a combination of excellent detective performance ( $3.75\times 10^{12}$ Jones detectivity and $1\times 10^{3}\text{A}$ /W responsivity) and electrical performance (small 3-V threshold voltage, 0.53-V/decade substhreshold slop, and 0.1-V hysteretic threshold voltage’s shift). Additionally, this dual-gate phototransistor exhibits high stability and accelerated detecting speed ( $ ) due to the inorganic perovskite QDs/PMMA hybrid gate insulator. Our results suggest that in a proper device architecture, perovskite nanomaterials can be promising candidates for cost-effective, high-performance phototransistor.