Large-area Growth Research Articles

The etching effect of oxygen during the cooling process of graphene CVD synthesis

Chemical vapor deposition provides a promising approach for the growth of large-area, high-quality graphene on Cu substrates. Oxygen plays either positive or negative roles for graphene synthesis, which have been extensively investigated predominantly focusing on graphene nucleation and growth stages. This study investigates the influence of oxygen during the cooling phase and demonstrates that graphene is more resistant to oxygen at higher temperatures but becomes susceptible to etching as the temperature decreases, unless it is too low. Thermodynamic simulations reveal that at elevated temperatures, oxygen is consumed by methane in the gas phase, leading to the generation of reactive carbon species that promote graphene growth and inhibit etching. Additionally, the etching reactivity of graphene is found to be correlated with the surface orientation of the underlying Cu grains. These findings suggest that defects in graphene can arise during the cooling stage if oxidant impurities in the atmosphere are not adequately controlled. Strategies to suppress graphene etching during cooling, such as reducing oxidant impurities and increasing cooling rates, are also presented.

Wafer scale and substrate-agnostic growth of MoS2 nanowalls for efficient electrocatalytic hydrogen generation in acidic and alkaline media

Emerging as a promising alternative to expensive platinum-based catalysts for electrocatalytic hydrogen evolution reaction (HER), molybdenum disulfide (MoS2) stands out for its favourable thermodynamic properties. However, the catalytic activity of MoS2 is mostly confined to its edges while the basal plane remains inactive, limiting practical applicability. Fabrication of stable MoS2 structures with enhanced active sites on a given surface area still remains a complex task. Here we introduce a substrate-agnostic, metal-organic chemical vapour deposition (MOCVD) method for large-area 3D dendritic nanostructures of 2D MoS2, termed as “MoS2 nanowalls”. Using scanning and transmission electron microscopy (SEM/TEM), we elucidate the growth mechanism of the MoS2 nanowalls and their branched dendritic structure. Even subjected to extreme pH environments (0 and 14) during the HER, the grown MoS2 nanowalls show remarkable stability even after >170 hours of continuous operation and exhibit excellent catalytic activity with 10 mAcm−2 current density achievable by applying low overpotentials (309±2 mV at pH = 0 and 272±2 mV at pH = 14). The presented large-area growth method for inexpensive MoS2 nanowall based catalyst can pave the way for practical applications of water electrolysis cells operating at low voltages (≤1.5 V).

Large-Area Epitaxial Growth of Transition Metal Dichalcogenides.

Over the past decade, research on atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs) has expanded rapidly due to their unique properties such as high carrier mobility, significant excitonic effects, and strong spin-orbit couplings. Considerable attention from both scientific and industrial communities has fully fueled the exploration of TMDs toward practical applications. Proposed scenarios, such as ultrascaled transistors, on-chip photonics, flexible optoelectronics, and efficient electrocatalysis, critically depend on the scalable production of large-area TMD films. Correspondingly, substantial efforts have been devoted to refining the synthesizing methodology of 2D TMDs, which brought the field to a stage that necessitates a comprehensive summary. In this Review, we give a systematic overview of the basic designs and significant advancements in large-area epitaxial growth of TMDs. We first sketch out their fundamental structures and diverse properties. Subsequent discussion encompasses the state-of-the-art wafer-scale production designs, single-crystal epitaxial strategies, and techniques for structure modification and postprocessing. Additionally, we highlight the future directions for application-driven material fabrication and persistent challenges, aiming to inspire ongoing exploration along a revolution in the modern semiconductor industry.

Low temperature self-growth of organic-inorganic perovskite nanowires for high performance flexible photodetectors

There has been a huge drive to explore flexible photodetectors for the large area growth of wearable, bendable, repeatable and lightweight electronics. This work describes the large-area ordered growth of MAPbI3 nanowires on PET (polyethylene terephthalate) by self-growth method at low temperature. The devices made of MAPbI3 nanowire exhibit high detectivity and responsivity of 2.403 × 1011 Jones and 7.62 A/W, respectively. Subsequently, the devices are bent at different angles (10°, 20°, 30°, 40° and 50°) and the on/off ratio of the photodetectors decreased by only 18.8 %. The device also maintained an extremely high photocurrent (a retention rate of 84.8 %) after 1000 bending cycles at 50°. Furthermore, the fluctuations of photocurrents and dark currents are small (fluctuating ∼4 %) after repeatedly bending in the range of 0° and 50° for 150 times, revealing that the MAPbI3 nanowire flexible photoelectronic device possesses good mechanical stability and excellent repeatability. Compared with that of the non-encapsulation device, the long-term stability of the encapsulated device is improved by 52.15 %. The simulation results also show that the photocurrent changes slightly with the change of bending angle, which further verifies that the MAPbI3 nanowires possesses advanced flexibility and stability at low bending angle. This method offers a straightforward and efficient way to prepare flexible photodetectors with high performance.

Epitaxial Growth of the Large-Scale, Highly-Ordered 3D GaN-Truncated Pyramid Array Toward an Ultrahigh Rejection Ratio and Responsivity Visible-Blind Ultraviolet Photodetection.

The micro- and nanostructures of III-nitride semiconductors captivate strong interest owing to their distinctive properties and myriad potential applications. Nevertheless, challenges endure in managing the damage inflicted on crystals through top-down processes or achieving extensive control over the large-area growth of these microstructures via bottom-up methods, thereby impacting their optical and electronic properties. Here, we present novel epitaxially grown 3D GaN truncated pyramid arrays (TPAs) on patterned Si substrates, devoid of any catalyst. These GaN TPAs feature highly ordered, large-scale structures, attributed to the utilization of 3D Si substrates and thin AlN interlayers to alleviate epitaxial strains and limit dislocation formation. Comprehensive characterization via scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and cathodoluminescence attests to the superior structural and optical attributes of these crystals. Furthermore, photoluminescence and ultraviolet (UV)-visible diffuse reflectance spectroscopy reveal sharp band-edge emission and significant light trapping in the UV bands. Employing these GaN TPAs, we constructed metal-semiconductor-metal visible-blind UV photodetectors (PDs) incorporating Ti3C2 MXene as Schottky electrodes. These PDs display exceptional responsivity, achieving 5.32 × 103 mA/W at 255 nm and an ultrahigh UV/visible rejection ratio (R255nm/R450nm) approaching 106, which are 1-2 orders of magnitude higher than most recently reported works. This exploration showcases novel GaN-based microstructures characterized by uniformity, ordered geometry, and exemplary crystalline integrity, paving the way for developing optoelectronic applications.

Tailoring MoS2 domains size, doping, and light emission by the sulfurization temperature of ultra-thin MoOx films on sapphire

Thermal sulfurization of ultra-thin Mo-based films represents a promising approach for large-area growth of MoS2. In this paper, we demonstrated that the crystalline quality (domains size and defects density), strain, doping, and light emission properties of monolayer (1L) MoS2 obtained from sputter deposited MoOx films on a c-sapphire substrate can be tailored by the sulfurization temperature (Ts) in the range from 700 to 800 °C. Starting from a continuous film with a nanocrystalline domains structure at Ts = 700 °C, a distribution of 1L MoS2 triangular domains with 2.1 ± 0.6 and 2.6 ± 1.6 μm average sizes was obtained by increasing Ts to 750 and 800 °C, respectively. The increase in Ts was accompanied by a strong (25×) enhancement of the photoluminescence (PL) intensity. Furthermore, the average doping of MoS2, evaluated from Raman analyses, evolved from a strong p-type doping (∼1 × 1013 cm−2) after Ts = 700 °C, ascribed to residual MoO3 in the film, to a low average n-type doping (∼0.04 × 1013 cm−2) after Ts = 800 °C. The wide tunability of doping and PL of 1L MoS2 by the sulfurization temperature can be exploited to tailor material properties for different specific applications.

Synthesis of Few-Layer Hexagonal Boron Nitride for Magnetic Tunnel Junction Application.

Hexagonal boron nitride (hBN), a wide-gap two-dimensional (2D) insulator, is an ideal tunneling barrier for many applications because of the atomically flat surface, high crystalline quality, and high stability. Few-layer hBN with a thickness of 1-2 nm is an effective barrier for electron tunneling, but the preparation of few-layer hBN relies on mechanical exfoliation from bulk hBN crystals. Here, we report the large-area growth of few-layer hBN by chemical vapor deposition on ferromagnetic Ni-Fe thin films and its application to tunnel barriers of magnetic tunnel junction (MTJ) devices. Few-layer hBN sheets mainly consisting of two to three layers have been successfully synthesized on a Ni-Fe catalyst at a high growth temperature of 1200 °C. The MTJ devices were fabricated on as-grown hBN by using the Ni-Fe film as the bottom ferromagnetic electrode to avoid contamination and surface oxidation. We found that trilayer hBN gives a higher tunneling magnetoresistance (TMR) ratio than bilayer hBN, resulting in a high TMR ratio up to 10% at ∼10 K.

CVD growth of large-area, continuous, and defect-free MoS2 multilayer films from solution-cast seed nanoflakes

Defects in transition metal dichalcogenides are among the primary source of their chemical reactivity, including their response to water. The CVD growth of defect-free continuous molybdenum disulfide (MoS2) films has been particularly challenging. In this work, we demonstrate the growth of large-area continuous films of MoS2 using solution-cast MoS2 seed nanoflakes, both with and without the assistance of alkali halide. The MoS2 seed nanoflakes serve as nucleation sites for the in-plane growth of few-layer MoS2, which is accompanied by localized vertical growth of MoS2 particles. For films grown with the combination of seed and NaCl, very low oxygen content was observed together with the stoichiometric ratio of Mo: S being close to the ideal value of 1: 2. These films show humidity-insensitive electrical response over a wide interval (5%–95% RH). This is attributed to very low concentrations of edge and basal-plane defects, leading to low water dissociation and restricted proton transport.

Low-Temperature Synthesis of WSe2 by the Selenization Process under Ultrahigh Vacuum for BEOL Compatible Reconfigurable Neurons.

Low-temperature large-area growth of two-dimensional (2D) transition-metal dichalcogenides (TMDs) is critical for their integration with silicon chips. Especially, if the growth temperatures can be lowered below the back-end-of-line (BEOL) processing temperatures, the Si transistors can interface with 2D devices (in the back end) to enable high-density heterogeneous circuits. Such configurations are particularly useful for neuromorphic computing applications where a dense network of neurons interacts to compute the output. In this work, we present low-temperature synthesis (400 °C) of 2D tungsten diselenide (WSe2) via the selenization of the W film under ultrahigh vacuum (UHV) conditions. This simple yet effective process yields large-area, homogeneous films of 2D TMDs, as confirmed by several characterization techniques, including reflection high-energy electron diffraction, atomic force microscopy, transmission electron microscopy, and different spectroscopy methods. Memristors fabricated using the grown WSe2 film are leveraged to realize a novel compact neuron circuit that can be reconfigured to enable homeostasis.

Improved photoelectrochemical performance of tungsten-catalyzed graphene nanoplatelet electrodes prepared by hot-wire chemical vapor deposition at low substrate temperatures

The current increase in demand for graphene in various energy applications such as electrode materials for supercapacitors, batteries, thermoelectric, and hydrogen production via water-splitting, the production of high-quality graphene, considering its fascinating physical and electrical properties, high-yield, and large-area has becoming more challenging at the research and development level. Therefore, in this work, graphene nanoplatelets (GNPs) were directly grown on tungsten nanoparticle (W NP)-coated p-type crystalline silicon and quartz substrates using hot-wire chemical vapor deposition at low substrate temperatures (<500 °C). Prior to the GNP deposition, a plasma process was employed to induce the formation of W NPs, which act as a metal catalyst for facilitating the growth of large-area and multi-layer GNPs. The W NPs were formed at substrate temperatures ranging from 250 to 550 °C, with the largest graphene sheet was grown at 450 °C. Higher substrate temperatures promote the growth of high-quality graphene layers with high intensities of G (IG) and 2D bands (I2D), and high I2D/IG ratio values. The GNP photoelectrode prepared at 450 °C demonstrated better photoelectrochemical responses with the highest photocurrent density of 1.65 mA/cm2 at 1.5 VAg/AgCl, the lowest charge transfer resistance (14.0 kΩ), and the highest donor density (2.57 × 10 28 cm−3) compared to the tungsten carbide thin film and W NP electrodes prepared at the same temperature. The effects of substrate temperature on the optical, structural, and photoelectrochemical properties of the as-grown GNPs are discussed.

Large-area growth of synaptic heterostructure arrays for integrated neuromorphic visual perception chips

Two-dimensional (2D) metal chalcogenides have garnered significant attention as promising candidates for novel neuromorphic synaptic devices due to their exceptional structural and optoelectronic properties. However, achieving large-scale integration and practical applications of synaptic chips has proven challenging due to significant hurdles in materials preparation and the absence of effective nanofabrication techniques. In a recent breakthrough, we introduced a revolutionary allopatric defect-modulated Fe7S8@MoS2 synaptic heterostructure, which demonstrated remarkable optoelectronic synaptic response capabilities. Building upon this achievement, our current study takes a step further by presenting a sulfurization-seeding synergetic growth strategy, enabling the large-scale and arrayed preparation of Fe7S8@MoS2 heterostructures. Moreover, we developed a 3D vertical integration technique for the fabrication of arrayed optoelectronic synaptic chips. Notably, we have successfully simulated the visual persistence function of the human eye using our arrayed chip. Our synaptic devices exhibit a remarkable ability to replicate the preprocessing functions of the human visual system, resulting in significantly improved noise reduction and image recognition efficiency. This study might mark an important milestone in advancing the field of optoelectronic synaptic devices, significantly prompting the development of mature integrated visual perception chips.

Universal Strategy for Metal-Organic Framework Growth: From Cascading-Functional Films to MOF-on-MOFs.

Transformation of metal-organic framework (MOF) particles into thin films is urgently needed for the persistent development of well-applicable devices, and recently emerging functional-integrated hybrid frameworks. Although some flexible polymers and exclusive modification approaches have been proposed, the additive-free and widely applicable strategy has not been reported, hampering the deep investigation of the structure-performance relationship. A universal strategy for the in situ growth of large-area and continuous MOF films with controllable microstructures is introduced, through the modification of multi-scale and multi-structure substrates with poly(4-vinylpyridine) as the anchor to capture metal ions via Coulomb attraction. Based on the clarified structure-adsorption-separation mechanisms, the customized devices fabricated by in situ growth can achieve highly selective adsorption and excellently synergetic separation of various industrially relevant isomers. In addition, this strategy is also feasible for the construction of MOF-on-MOFs with varied lattice parameters. This strategy is easy to implement and will be widely applicable to the surface growth of diverse MOFs on desired substrates, and provides a new concept for developing hybrid MOFs integrating with customized functionalities.

Seeded growth of single-crystal black phosphorus nanoribbons.

Two-dimensional materials have emerged as an important research frontier for overcoming the challenges in nanoelectronics and for exploring new physics. Among them, black phosphorus, with a combination of a tunable bandgap and high mobility, is one of the most promising systems. In particular, black phosphorus nanoribbons show excellent electrostatic gate control, which can mitigate short-channel effects in nanoscale transistors. Controlled synthesis of black phosphorus nanoribbons, however, has remained an outstanding problem. Here we report large-area growth of black phosphorus nanoribbons directly on insulating substrates. We seed the chemical vapour transport growth with black phosphorus nanoparticles and obtain uniform, single-crystal nanoribbons oriented exclusively along the [100] crystal direction. With comprehensive structural calculations, we discover that self-passivation at the zigzag edges holds the key to the preferential one-dimensional growth. Field-effect transistors based on individual nanoribbons exhibit on/off ratios up to ~104, confirming the good semiconducting behaviour of the nanoribbons. These results demonstrate the potential of black phosphorus nanoribbons for nanoelectronic devices and also provide a platform for investigating the exotic physics in black phosphorus.

High yield and wide lateral size growth of α-Mo2C: exploring the boundaries of CVD growth of bare MXene analogues

Synthesis of Mo2C bare MXenes, without surface terminations groups, via chemical vapor deposition (CVD) on metal foils is scientifically a very intriguing crystal growth process, and there are still challenges and limited fundamental understanding to overcome to obtain high yield and wide crystal size lateral growth. Achieving large area coverage via direct growth is scientifically vital to utilize the full potential of their unique properties in different applications. In this study, we sought to expand the boundaries of the current CVD growth approach for Mo2C MXenes and gain insights into the possibilities and limitations of large area growth, with a particular focus on controlling Mo concentration. We report a facile modification of their typical CVD growth protocol and show its influence on the Mo2C synthesis, with growth times spanning up to 3 h. Specifically, prior to initiating the CVD growth process, we introduced a holding step in temperature at 1095 °C. This proved to be beneficial in increasing the Mo concentration on the liquid Cu growth surface. We achieved an average Mo2C crystals coverage of approximately 50% of the growth substrate area, increased tendency of coalescence and merging of individual flakes, and lateral flake sizes up to 170 μm wide. To gain deeper understanding into their CVD growth behavior, we conducted a systematic investigation of the effect of several factors, including (i) a holding step time on Mo diffusion rate through molten Cu, (ii) the Cu foil thickness over the Mo foil, and (iii) the CVD growth time. Phase, chemical and microstructural characterization by x-ray diffraction, x-ray photon spectroscopy, SEM and scanning/transmission electron microscopy revealed that the grown crystals are single phase α-Mo2C. Furthermore, insights gained from this study sheds light on crucial factors and inherent limitations that are essential to consider and may help guide future research progress in CVD growth of bare MXenes.

Reconfiguring nucleation for CVD growth of twisted bilayer MoS2 with a wide range of twist angles

Twisted bilayer (TB) transition metal dichalcogenides (TMDCs) beyond TB-graphene are considered an ideal platform for investigating condensed matter physics, due to the moiré superlattices-related peculiar band structures and distinct electronic properties. The growth of large-area and high-quality TB-TMDCs with wide twist angles would be significant for exploring twist angle-dependent physics and applications, but remains challenging to implement. Here, we propose a reconfiguring nucleation chemical vapor deposition (CVD) strategy for directly synthesizing TB-MoS2 with twist angles from 0° to 120°. The twist angles-dependent Moiré periodicity can be clearly observed, and the interlayer coupling shows a strong relationship to the twist angles. Moreover, the yield of TB-MoS2 in bilayer MoS2 and density of TB-MoS2 are significantly improved to 17.2% and 28.9 pieces/mm2 by tailoring gas flow rate and molar ratio of NaCl to MoO3. The proposed reconfiguring nucleation approach opens an avenue for the precise growth of TB-TMDCs for both fundamental research and practical applications.

Large Area Growth of Silver and Gold Telluride Ultrathin Films via Chemical Vapor Tellurization

Developing a method for the growth of ultrathin metal chalcogenides, potentially targeting the two-dimensional (2D) limit, has a pivotal impact on various nanotechnological device applications. Here, we employed a vapor deposition scheme, based on tellurization, to induce the heterogenous chemical reaction between solid Ag and Au precursors, in the form of ultrathin films, and Te vapors. We characterized the morphological and structural properties of the grown tellurides by using atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction techniques. The developed tellurization methodology provides a key advancement in the picture of growing ultrathin noble metal tellurides and holds great potential for applications in different technological fields.

Diamond deposition on AlN using Q-carbon interlayer through overcoming the substrate limitations

Q-carbon, a quenched form of carbon, is a recently discovered carbon structure that has tremendous properties, compatibility, and potential for use in device fabrication and other electronic and mechanical applications. However, the non-equilibrium nature of the synthesis process and a very small window of growth parameters have limited the formation of Q-carbon to only low thermal conductive substrates. This study aims to overcome these limitations through extensive tuning of the parameters of diamond-like-carbon (DLC), the base structure required for the formation of Q-carbon. The as-deposited DLC films demonstrate ID/IG ratios ranging from 0.12 to 1.67, which are obtained through the optimization of laser energy density, rep rate, and deposition temperature during pulsed laser deposition. Utilizing Simulation of Laser Interaction with Materials, pulsed laser annealing (PLA) was used to directly transform the DLC films into Q-carbon while varying the PLA energy density from 0.3 J/cm2 to 1.2 J/cm2. Findings of Q-carbon formation on sapphire using different DLC films assisted in the preparation of a roadmap for overcoming the substrate limitations for Q-carbon formation. Further, Q-carbon is formed on AlN substrates for the direct deposition of diamond films without the requirement of a non-carbon interfacial layer or nanodiamond seeding layer. The large-area and uniform diamond growth on Q-carbon shows well-faceted and five-fold twinned growth with a 70 % improvement in the residual compressive stress of diamond on AlN. Such a method of diamond deposition on AlN provides the opportunity to address the thermal management issues in wide- and ultra-wide bandgap high-power electronic devices.

Large-area single-crystal TMD growth modulated by sapphire substrates.

Transition metal dichalcogenides (TMDs) have recently attracted extensive attention due to their unique physical and chemical properties; however, the preparation of large-area TMD single crystals is still a great challenge. Chemical vapor deposition (CVD) is an effective method to synthesize large-area and high-quality TMD films, in which sapphires as suitable substrates play a crucial role in anchoring the source material, promoting nucleation and modulating epitaxial growth. In this review, we provide an insightful overview of different epitaxial mechanisms and growth behaviors associated with the atomic structure of sapphire surfaces and the growth parameters. First, we summarize three epitaxial growth mechanisms of TMDs on sapphire substrates, namely, van der Waals epitaxy, step-guided epitaxy, and dual-coupling-guided epitaxy. Second, we introduce the effects of polishing, cutting, and annealing processing of the sapphire surface on the TMD growth. Finally, we discuss the influence of other growth parameters, such as temperature, pressure, carrier gas, and substrate position, on the growth kinetics of TMDs. This review might provide deep insights into the controllable growth of large-area single-crystal TMDs on sapphires, which will propel their practical applications in high-performance nanoelectronics and optoelectronics.

Effective concentration ratio driven phase engineering of MBE-grown few-layer MoTe2.

The polymorphic nature of ultrathin transition metal dichalcogenide (TMDC) materials makes the phase engineering of these materials an interesting field of investigation. Understanding the phase-controlling behavior of different growth parameters is crucial for obtaining large-area growth of a desirable phase. Here, we report a detailed study on the effect of growth parameters for engineering different phases of few-layer MoTe2 on sapphire using molecular beam epitaxy (MBE). Our study shows that the 2H phase of MoTe2 is stabilized in a certain regime of the flux ratio and growth temperature, while on both the lower, as well as, the higher sides of this regime, the 1T' phase is favored. The combined effect of growth parameters is explained using the effective concentration ratio of Te and Mo at the growth surface, which is found to be the primary factor governing the phase selectivity in few-layer MoTe2. XPS and KPFM investigations show the contribution of excess carrier doping in driving the phase change. The effect of the sapphire substrate on the crystallinity and phase-dependent morphological features has also been studied. This knowledge of versatile and controlled phase engineering of few-layer MoTe2 paves the way for fabricating large-scale hetero-phase-based metal-semiconductor heterostructures for future electronic and optoelectronic device applications.

(Digital Presentation) Present Status and Future Prospects of Large Area Growth and Devices of Two-Dimensional Materials

2D noble metal di- chalcogenides (NMDC or NMC) materials have attracted enormous research interests due to their novel physical and chemical properties with confined dimensions. Here we present two of our experimental works in investigating the growth of PtS and PtSx. (i) Platinum monosulfide as one of the most common platinum-group minerals has been less studied due to either the low purity in the natural product or the extremely high-pressure conditions for synthesis. Recently, platinum monosulfide (PtS) 2D membranes have emerged as rising-star materials for fundamental Raman and X-ray photoelectron spectral analysis as well as device exploration. However, a large-area homogeneous synthesis route has not yet been proposed and released. In this communication, we report a facile metal sulfurization strategy for the synthesis of a 4-inch wafer-scale PtS film. Enhanced characterization tools have been employed for thorough analysis of the crystal structure, chemical environment, vibrational modes, and atomic configuration. Furthermore, through theoretical calculations the phase diagram of the Pt–S compound has been plotted for showing the successful formation of PtS in our synthesis conditions. Eventually, a high-quality PtS film has been reflected in device demonstration by a photodetector. Our approach may shed light on the mass production of PtS films with precise control of their thickness and homogeneity as well as van der Waals heterostructures and related electronic devices. (ii) PtSx, as a more recent 2D material that aroused extensive research interests, has been applied in electronic and optoelectronic devices because of its excellent electronic characteristics and commendable stability. However, the synthesis of large-scale uniform PtSx remains a challenge. Here we studied a modified chemical vapor deposition (CVD) method to grow large-scale uniform PtSx films on SiO2/Si and c-plane sapphire substrates, which can avoid some disadvantages of the mechanical exfoliation method in the device fabrication. The large area uniform PtSx films are achieved through Pt sulfurization using H2S gas, replacing the sulfur powder in traditional methods, as the sulfur source. The material characterizations successfully proved that our modified CVD method is feasible and repeatable, and the PtSx film can be synthesized on different substrates. The PtSx photodevices show good photoresponse properties with a wide spectrum response range. The PtSx/sapphire device shows a better photoresponse in terms of the detectivity (9.17 × 109 Jones) and the responsivity (0.31 A W−1) than that of the PtSx/SiO2/Si device in our experiment, as well as one-year air stability, which may be caused by the different PtSx film quality due to a lattice mismatch difference between the PtSx and the different substrates. These results offer the design and synthesis technology for large-scale, uniform, and stable PtS and PtSx film, as well as an example of photoresponse-enhanced devices which could be generalizable to other transition metal dichalcogenides (TMDCs) and devices for future development and applications. Figure 1