2D Thin Films Research Articles

Progress and challenges in the synthesis of two-dimensional Van der Waals ferroic materials and heterostructures

Abstract Two-dimensional ferroelectric and magnetic van der Waals materials are emergent platforms for the discovery of novel cooperative quantum phenomena and development of energy-efficient logic and memory applications as well as neuromorphic and topological computing. This review presents a comprehensive survey of the rapidly growing 2D ferroic family from the synthesis perspective, including brief introductions to the top-down and bottom-up approaches for fabricating 2D ferroic flakes, thin films, and heterostructures as well as the important characterization techniques for assessing the sample properties. We also discuss the key challenges and future directions of the field, including scalable growth, property control, sample stability, and integration with other functional materials.

Making 2D Materials Sparkle in Energy Storage via Assembly.

ConspectusTwo-dimensional (2D) materials such as graphene and MXenes offer appealing opportunities in electrochemical energy storage due to their large surface area, tunable surface chemistry, and unique electronic properties. One of the primary challenges in utilizing these materials for practical electrodes, especially those with industrial-level thickness, is developing a highly interconnected and porous conductive network. This network is crucial for supporting continuous electron transport, rapid ion diffusion, and effective participation of all active materials in electrochemical reactions. Moreover, the demand for efficient energy storage in advanced electronic devices and electric vehicles has led to the need for not only thicker but also denser electrodes to achieve compact energy storage. Traditional densification methods often compromise between volumetric capacitance and ion-accessible surface area, which can diminish rate performance. As versatile building blocks, 2D materials can overcome these limitations through the assembly into complex superstructures such as 1D fibers, 2D thin films, and 3D porous networks, a capability less attainable by other nanomaterials.This Account explores the pathways from exfoliated 2D nanosheets to densely packed, yet porous assemblies tailored for compact energy storage. Focusing on graphene and MXenes, we delve into the intricate relationships between surface structure, assembly behaviors, and electrochemical performance. We emphasize the crucial role of surface chemistry and interfacial interactions in forming stable colloidal dispersions and subsequent macroscopic structures. Furthermore, we highlight how solvents, acting as spacers, are instrumental in microstructure formation and how capillary force-driven densification is essential for creating compact assemblies. With precise control over shrinkage, the customized dense assemblies can strike a balance between high packing density and sufficient porosity, ensuring efficient ion transport, mechanical stability, and high volumetric performance across various electrochemical energy storage technologies.Furthermore, we highlight the importance of understanding and manipulating the surface chemistry of 2D materials at the atomic level to optimize their assembly and enhance electrochemical behaviors. Advanced in situ characterizations with high temporal and spatial resolution are necessary to gain deeper insights into the complex assembly process. Moreover, the integration of machine learning and computational chemistry emerges as a promising method to predict and design new materials and assembly strategies, potentially accelerating the development of next-generation energy storage systems. Our insights into the assembly and densification of 2D materials provide a comprehensive foundation for future research and practical applications in compact, high-performance energy storage devices. This exploration sets the stage for a transformative approach to overcoming the challenges of current energy storage technologies, promising significant advancements in 2D materials in the field.

(Invited) Designer 2D Materials and Machine-Learning Assisted Characterization

2D materials offer enormous opportunities to build designer structures with widely tunable properties. The precise atomic engineering and quick characterization approach are critical to advance the application of designer 2D materials. This talk will introduce new optical features of designer 2D materials [1-4] with a focus on atomic substitution in monolayer WS2 [1]. The engineering of 2D materials presents unique opportunities for optoelectronic device and quantum information platform. When designing optoelectronic devices of 2D materials, spectroscopic permittivity of 2D material is a key parameter. While ellipsometry has been used to measure permittivity, it requires simple device structure, non-trivial parameter fitting, and special setup. This talk will also present a new machine-learning assisted approach to measure permittivity of 2D materials embedded in complex device structures without model fitting, which can facilitate a quick, accurate, and in-situ characterization of 2D and other thin film materials [5].

Inkjet-Printed, High-Performance MoS2 Transistors and Unipolar Logic Electronics.

Two-dimensional (2D) semiconductor field-effect film transistors combine large carrier mobility with mechanical flexibility and therefore can be ideally suitable for wearable electronics or at the sensor interfaces of smart sensor systems. However, such applications require large-area solution processing as opposed to single-flake devices, where the critical challenge to overcome is the high interflake resistance values. In this report, using a narrow-channel, near-vertical transport device architecture, we have fabricated inkjet-printed sub-20 nm channel electrolyte-gated transistors with predominantly intraflake carrier transport. Therefore, the electronics transport in these transistors is not dominated by the high interflake resistance, and the intraflake material properties including doping density, defect concentration, contact resistance, and threshold voltage modulation can be examined and optimized independently to achieve a current density as high as 280 μA·μm-1. In addition, through the passivation of the sulfur vacancies with a tailored surface treatment, we demonstrate an impressive On-Off current ratio exceeding 1 × 107, complemented by a low subthreshold swing of 100 mV·decade-1. Next, exploiting these high-performance transistors, unipolar depletion-load-type inverters have been fabricated that show a maximum gain of 31. Furthermore, we have realized NAND, NOR, and OR gates, demonstrating their seamless operation at a frequency of 1 kHz. Therefore, this work represents an important step forward to realize electronic circuits based on printed 2D thin film transistors.

Stereointerface Structure Drives Ferroelectricity in BaZrO3 Films.

Interfacial strain engineering can induce structural transformation and introduce new physical properties into materials, which is an effective method to prepare new multifunctional materials. However, interfacial strain has a limited spatial impact size. For example, in 2D thin films, the critical thickness of biaxial strain is typically less than 20 nm, which is not conducive to the maintenance of a strained structure and properties in thick film materials. The construction of a 3D interface can solve this problem. The large lattice mismatch between the BaZrO3 thin film and the substrate can induce the out-of-phase boundary (OPB) structure, which can extend along the thickness direction with the stacking of atoms. The lattice distortion at the OPB structure can provide a clamping effect for each layer of atoms, thus expanding the spatial influence range of biaxial strain. As a result, the uniform in-plane strain distribution and strain-induced ferroelectricity (Pr = 13 μC/cm2) are maintained along the thickness direction in BaZrO3 films.

Demonstration of Controlled Skyrmion Injection Across a Thickness Step.

Spintronic devices incorporating magnetic skyrmions have attracted significant interest recently. Such devices traditionally focus on controlling magnetic textures in 2D thin films. However, enhanced performance of spintronic properties through the exploitation of higher dimensionalities motivates the investigation of variable-thickness skyrmion devices. We report the demonstration of a skyrmion injection mechanism that utilizes charge currents to drive skyrmions across a thickness step and, consequently, a metastability barrier. Our measurements show that under certain temperature and field conditions skyrmions can be reversibly injected from a thin region of an FeGe lamella, where they exist as an equilibrium state, into a thicker region, where they can only persist as a metastable state. This injection is achieved with a current density of 3 × 108 A m-2, nearly 3 orders of magnitude lower than required to move magnetic domain walls. This highlights the possibility to use such an element as a skyrmion source/drain within future spintronic devices.

Superconductivity in atomically thin films: Two-dimensional critical state model

The comprehensive understanding of superconductivity is a multiscale task that involves several levels, starting from the electronic scale determining the microscopic mechanism, going to the phenomenological scale describing vortices and the continuum-elastic scale describing vortex matter, to the macroscopic scale relevant in technological applications. The prime example for such a macro-phenomenological description is the Bean model that is hugely successful in describing the magnetic and transport properties of bulk superconducting devices. Motivated by the development of novel devices based on superconductivity in atomically thin films, such as twisted-layer graphene, here, we present a simple macro-phenomenological description of the critical state in such two-dimensional (2D) thin films. While transverse screening and demagnetization can be neglected in these systems, thereby simplifying the task in comparison with usual film- and platelet-shaped samples, surface and bulk pinning are important elements to be included. We use our 2D critical state model to describe the transport and magnetic properties of 2D thin-film devices, including the phenomenon of nonreciprocal transport in devices with asymmetric boundaries and the superconducting diode effect. Published by the American Physical Society 2024

Interfacing Langmuir-Blodgett and Pickering Emulsions for the Synthesis of 2D Nanostructured Films: Applications in Copper Ion Adsorption.

This research focuses on developing a 2D thin film comprising a monolayer of silica nanoparticles functionalized with polyethyleneimine (PEI), achieved through a novel integration of Langmuir-Blodgett (L-B) and Pickering emulsion techniques. The primary aim was to create a nanostructured film that exhibits dual functionality: iridescence and efficient metal ion adsorption, specifically Cu(II) ions. The methodology combined L-B and Pickering emulsion polymerization to assemble and stabilize a nanoparticle monolayer at an oil/water interface, which was then polymerized under UV radiation to form an asymmetrically structured film. The results demonstrate that the film possesses a high adsorption efficiency for Cu(II) ions, with the enhanced mechanical durability provided by a reinforcing layer of polyvinyl alcohol/glycerol. The advantage of combining L-B and Pickering emulsion technology is the ability to generate 2D films from functional nanoparticle monolayers that are sufficiently sturdy to be deployed in applications. The 2D film's practical applications in environmental remediation were confirmed through its ability to adsorb and recover Cu(II) ions from aqueous solutions effectively. We thus demonstrate the film's potential as a versatile tool in water treatment applications owing to its combined photonic and adsorptive properties. This work paves the way for future research on the use of nanoengineered films in environmental and possibly photonic applications focusing on enhancing the film's structural robustness and exploring its broader applicability to other pollutants and metal ions.

Differential pressure sensors based on transfer-free piezoresistive layered PdSe2 thin films

Piezoresistive layered two-dimensional (2D) crystals offer intriguing promise as pressure sensors for microelectromechanical systems (MEMS) due to their remarkable strain-induced conductivity modulation. However, integration of the conventional chemical vapor deposition grown 2D thin films onto a micromachined silicon platform requires a complex transfer process, which degrades their strain-sensing performance. In this study, we present a differential pressure sensor built on a transfer-free piezoresistive PdSe2 polycrystalline film deposited on a SiN x membrane by plasma-enhanced selenization of a metal film at a temperature as low as 200 °C. Based on the resistance change and finite element strain analysis of the film under membrane deflection, we show that a 7.9 nm thick PdSe2 film has a gauge factor (GF) of −43.3, which is ten times larger than that of polycrystalline silicon. The large GF enables the development of a diaphragm pressure sensor with a high sensitivity of 3.9 × 10−4 kPa−1 within the differential pressure range of 0–60 kPa. In addition, the sensor with a Wheatstone bridge circuit achieves a high voltage sensitivity of 1.04 mV·kPa−1, a rapid response time of less than 97 ms, and small output voltage variation of 8.1 mV in the temperature range of 25 °C to 55 °C. This transfer-free and low-temperature grown PdSe2 piezoresistive thin film is promising for MEMS transducer devices.

Simultaneous secondary electron microscopy in the scanning transmission electron microscope with applications for in situ studies.

Scanning/transmission electron microscopy (STEM) is a powerful characterization tool for a wide range of materials. Over the years, STEMs have been extensively used for in situ studies of structural evolution and dynamic processes. A limited number of STEM instruments are equipped with a secondary electron (SE) detector in addition to the conventional transmitted electron detectors, i.e. the bright-field (BF) and annular dark-field (ADF) detectors. Such instruments are capable of simultaneous BF-STEM, ADF-STEM and SE-STEM imaging. These methods can reveal the 'bulk' information from BF and ADF signals and the surface information from SE signals for materials <200 nm thick. This review first summarizes the field of in situ STEM research, followed by the generation of SE signals, SE-STEM instrumentation and applications of SE-STEM analysis. Combining with various in situ heating, gas reaction and mechanical testing stages based on microelectromechanical systems (MEMS), we show that simultaneous SE-STEM imaging has found applications in studying the dynamics and transient phenomena of surface reconstructions, exsolution of catalysts, lunar and planetary materials and mechanical properties of 2D thin films. Finally, we provide an outlook on the potential advancements in SE-STEM from the perspective of sample-related factors, instrument-related factors and data acquisition and processing.

The ionization energy of α-sexithiophene and p-sexiphenyl in 2D and 3D thin films grown on silicon oxide surfaces.

The ionization energy (IE) of molecular thin films is sensitive to the molecular environments surrounding ionized molecules. In this study, we investigate the evolution of the IE on dimension-controlled 2D and 3D thin films of rod-like molecules, namely α-sexithiophene (α-6T) and p-sexiphenyl (p-6P), grown on SiO2 surfaces via photoelectron yield spectroscopy. In 2D thin films, the IE of α-6T and p-6P showed nearly constant values of 4.93 eV and 5.50 eV, respectively. In 3D thin films, however, with increasing coverage, the IE of the α-6T thin films gradually decreased to 4.84 eV at 15 ML (ML: monolayer) and the IE of the p-6P thin films gradually increased to 5.65 eV at 7 ML. These experimental findings underline the less significant impact of the domain size on the IE in 2D thin films and the significant impact of the neighboring layers on the IE in 3D thin films.

Graphene Oxide 2D Thin Films for Integrated Devices Based on Thermo-Optic Effects

Graphene Oxide 2D Thin Films for Integrated Devices Based on Thermo-Optic Effects

Wafer scale growth of single crystal two-dimensional van der Waals materials.

Two-dimensional (2D) van der Waals (vdW) materials, including graphene, hexagonal boron nitride (hBN), and metal dichalcogenides (MCs), form the basis of modern electronics and optoelectronics due to their unique electronic structure, chemical activity, and mechanical strength. Despite many proof-of-concept demonstrations so far, to fully realize their large-scale practical applications, especially in devices, wafer-scale single crystal atomically thin highly uniform films are indispensable. In this minireview, we present an overview on the strategies and highlight recent significant advances toward the synthesis of wafer-scale single crystal graphene, hBN, and MC 2D thin films. Currently, there are five distinct routes to synthesize wafer-scale single crystal 2D vdW thin films: (i) nucleation-controlled growth by suppressing the nucleation density, (ii) unidirectional alignment of multiple epitaxial nuclei and their seamless coalescence, (iii) self-collimation of randomly oriented grains on a molten metal, (iv) surface diffusion and epitaxial self-planarization and (v) seed-mediated 2D vertical epitaxy. Finally, the challenges that need to be addressed in future studies have also been described.

Cathodic Deposition of Conductive MOF Films: Mechanism and Applications

Conductive metal-organic frameworks (MOFs) are porous yet electric conductive, promising for many applications such as electronics, electrocatalysts, and energy storage. However, traditional solvothermal and microwave synthesis methods usually lead to MOF powders that cannot be used directly, i.e., additional processes like adding binders, casting, and thermal treatments are required for their applications. Therefore, shaping conductive MOFs into 2D thin films is attracting attention from researchers. Here we report a cathodic deposition for the one-step fabrication of conductive MOF films, which features a fast and convenient deposition process. In this method, the deposition precursor contains metal salts and organic linkers (no supporting electrolyte is needed). When an external negative bias is applied on the conductive working electrode (WE), the linkers can be deprotonated on its surface. A conductive MOF film can thus be deposited on the WE by coordinating the deprotonated linkers and metal nodes. As demonstrating examples, Cu/Ni-HHTP (HHTP: 2,3,6,7,10,11-hexahydroxytriphenylene) and Cu-BTPA (BTPA: benzene-1,3,5-triyltriboronic acid) are cathodically deposited on indium-doped tin oxide (ITO) glass substrates. The measured conductivity of these deposited conductive MOF films varies from 0.01 to 0.1 S cm-1 depending on their thickness and composition. Both of the fabricated conductive MOF films show good performance on supercapacitors and electrochemical sensing.

Recent Advances on Pulsed Laser Deposition of Large-Scale Thin Films.

2D thin films, possessing atomically thin thickness, are emerging as promising candidates for next-generation electronic devices, due to their novel properties and high performance. In the early years, a wide variety of 2D materials are prepared using several methods (mechanical/liquid exfoliation, chemical vapor deposition, etc.). However, the limited size of 2D flakes hinders their fundamental research and device applications, and hence the effective large-scale preparation of 2D films is still challenging. Recently, pulsed laser deposition (PLD) has appeared to be an impactful method for wafer-scale growth of 2D films, owing to target-maintained stoichiometry, high growth rate, and efficiency. In this review, the recent advances on the PLD preparation of 2D films are summarized, including the growth mechanisms, strategies, and materials classification. First, efficacious strategies of PLD growth are highlighted. Then, the growth, characterization, and device applications of various 2D films are presented, such as graphene, h-BN, MoS2, BP, oxide, perovskite, semi-metal, etc. Finally, the potential challenges and further research directions of PLD technique is envisioned.

Nonsaturating Linear Magnetoresistance Manifesting Two-Dimensional Transport in Wet-Chemical Patternable Bi2O2Te Thin Films.

Two-dimensional (2D) materials with exotic transport behaviors have attracted extensive interest in microelectronics and condensed matter physics, while scaled-up 2D thin films compatible with the efficient wet-chemical etching process represent realistic advancement toward new-generation integrated functional devices. Here, thickness-controllable growth and chemical patterning of high-quality Bi2O2Te continuous films are demonstrated. Noticeably, except for an ultrahigh mobility (∼45074 cm2 V-1 s-1 at 2 K) and obvious Shubnikov-de Hass quantum oscillations, a 2D transport channel and large linear magnetoresistance are revealed in the patterned Bi2O2Te films. Investigation implies that the linear magnetoresistance correlates with the inhomogeneity described by P. B. Littlewood's theory and EMT-RRN theory developed recently. These results not only reveal the nonsaturating linear magnetoresistance in high-quality Bi2O2Te but shed light on understanding the corresponding physical origin of linear magnetoresistance in 2D high-mobility semiconductors and providing a pathway for the potential application in multifunctional electronic devices.

Constructing quasi-layered and self-hole doped SnSe oriented films to achieve excellent thermoelectric power factor and output power density

Thermoelectric (TE) technology can achieve the mutual conversion between electric energy and waste heat, and it has exhibited great prospects in multifunctional energy applications to alleviate the energy crisis. In the recent decade, SnSe has been explored widely because of its potentially high energy harvesting efficiency, green nature, and low cost. However, the relatively poor power factor (PF) derived from the intrinsic low carrier concentration (∼1017 cm−3) limits the output power density of the stoichiometric SnSe devices. Therefore, the advancement of novel optimization strategies for controlling carrier concentration is of utmost importance. Besides, compared with 3D bulks, 2D thin films are more compatible with modern semiconductor technology and have unique advantages in the construction and application of TE micro- and nano-devices. In this study, post-selenization technology were applied to increase the carrier concentration of the a-axis oriented SnSe epitaxial films utilizing the charge transfer and self-hole doped effects. The quasi-layered and self-hole doped films exhibited a high power factor of ∼5.9 µW cm−1 K−2 at 600 K along the in-plane direction when the carrier concentration is enhanced to ∼1018 cm−3 by increasing the selenization time to ∼20 min. The TE generator composed of four P-type film legs demonstrated the ultrahigh maximum power density of ∼83, ∼838 µW cm−2 at the temperature difference of ∼50 and ∼90 K, respectively. Post-selenization can effectively optimize the carrier concentration of SnSe-based materials, which is also feasible to other anion deficient TE films.

Phenomenological Interactions during CVT Synthesis of Large Scale MoS2

In the Chemical Vapor Transport (CVT), for deposition of MoS2, sulfur and MoO3 powder is evaporated at 200 0C and 650 0C respectively. The Ar flow directs the sulfur atoms to Mo species so as to react chemically as specified in the reactions in Equation-1. During the CVT process there is adsorption of MoS2 on Si/SiO2 substrate associated with the exhuast of SO2 as chemical reaction by-product. The MoS2 is deposited on the substrate by physisorption. Thus, in CVT, the nucleation and growth is a combined effect of chemisorption and physisorption. The three types of nucleation and growth theories for deposition of 2D thin films are presented by a. Volmer–Weber b.Frank–van der Merwe, c. Stranski–Krastanov in Figure 1.Figure 1[Equation 1]The mechanism for MoS2 nucleation and growth during CVT involves the evaporation of powdered precursors at a high temperature which leads to decomposition as well, followed by a chemical reaction. Temperature ramping-up rate, positioning of precursors, type and flow rate of carrier gases, Cooling rate, and pressure simultaneously determine the morphology, thickness, and crystallinity of the physisorbed MoS2. The highly simplified resolution of forces acting during the nucleation process is represented in Figure 2. The σF refers to the forces due to surface tension along the droplet, σS is the force exerted due to the energy associated with the substrate surface, and σFS is the force due to the interface energy between the droplet and the substrate. A little consideration of the comparison of the magnitude of these three forces leads to the determination of Growth Kinetics. When σS is smaller than the sum of σF and σFS, it favors Weber-Volmer theory; when σS is greater than the sum of σF and σFS, it favors Frank van der Merwe theory, and when the balance of this comparison fluctuates or is equal, it favors the Stranski–Krastanov growth model. In practice, the several parameters other than temperature, pressure, flow rate, and precursor flux that influence the nucleation and growth mechanism involve substrate surface texture, functionalization, availability of active cites, steric hindrance, Columbic interactions etc.Figure 2 Interactions in CVT on the basis of Scientific Theories : Considering that CVT involves the gas phase chemical reaction of precursors and physisorption for the MoS2 adsorption on the Si/SiO2 substrate, the modified ideal gas law can be applied more realistically with the introduction of the van der Waals parameters for intermolecular interaction forces ‘a’ and molecular size ‘b’. The modified gas law is stated by van der Waals equation as,[Equation 2]a – Constant for Intermolecular forces and b – Constant for Molecular size for the specified gas under consideration. Thus, if studies related to variation in temperature are carried out, Volume being physically constant and significantly large space in case of CVT may be considered as independent parameter. Thus, from relation 2, pressure is directly affected with the change in temperature.Further, the pressure in accordance with Amonton’s law affects the adsorption and mean free path of the Mo and S atoms that determines the reaction between the chemical species [3].The mean free path for the atomized precursor is expressed as follows.[Equation 3]The dependence of the mean free path λ on T – temperature and P – the pressure is conclusive for the parametric interactions resulting in accordance with the Amonton’s law for constant volume affect the CVT process. In the equation, is the Boltzman’s constant.As referred to in the beginning, physisorption is the mechanism for depositing 2D thin films in CVT. Physisorption is caused by adsorption and thus, the variation in process parameters will have impact on Langmuir’s adsorption [4]given by[Equation 4]Langmuir’s adsorption isotherm explains the interfacial interaction of the gas phase molecules with the substrate. The Figure 3. depicts the variation in corresponding to the KP at a constant temperature. As is evident the Langmuir’s adsorption is derived at isothermal conditions for variation in pressure. Thus, it is implied that during the CVT synthesis of MoS2 if the variation in temperature is studied, it will inherently affect the adsorption.Arrhenius equation [5] governs the reaction rate based on A- pre-exponent rate factor, Ea – activation energy, R – gas constant and temperature.[Equation 5]Considering the van der Waals equation and Amontons law, the temperature is going to affect the pressure. The rate constant will be affected by Ar flow rate. These phenomological interactions occur and influence the nucleation and large scale growth of MoS2 during CVT synthesis. Figure 1

Mechanical and magnetocaloric adjustable properties of Fe3O4/PET deformed nanoparticle film

The flexibility of nanoparticle films is a topic of rapidly growing interest in both scientific and engineering researches due to their numerous potential applications in a broad range of wearable electronics and biomedical devices. This article presents the elucidation of the properties of nanoparticle films. Here, a flexible film is fabricated based on polyethylene terephthalate (PET) and magnetic iron oxide at the nanoscale using layer-by-layer technology. The 2D thin flexible film material can be bent at different angles from 0° to 360°. With an increase in elastic deformation angles, the magnetocaloric effect of the film gradually increases in the alternating magnetic field. The test results from a vibrating sample magnetometer and a low-frequency impedance analyzer demonstrate that the film has a good magnetic response and anisotropy. The magnetocaloric effect and magnetic induction effect are controlled by deformation, providing a new idea for the application of elastic films. It combines the flexibility of the nanoparticle PET substrate and, in the future, it may be used for skin adhesion for administration and magnetic stimulation control.

Remarkable average thermoelectric performance of the highly oriented Bi(Te, Se)-based thin films and devices

Bi(Te, Se)-based compounds have attracted lots of attention for nearly two centuries as one of the most successful commercial thermoelectric (TE) materials due to their high performance at near room temperature. Compared with 3D bulks, 2D thin films are more compatible with modern semiconductor technology and have unique advantages in the construction of micro- and nano-devices. For device applications, high average TE performance over the entire operating temperature range is critical. Herein, highly c-axis-oriented N-type Bi(Te, Se) epitaxial thin films have been successfully prepared using the pulsed laser deposition technology by adjusting the deposition temperature. The film deposited at ∼260 °C demonstrate a remarkable average power factor (PFave) of ∼24.4 μW·cm−1·K−2 over the temperature range of 305–470 K, higher than most of the state-of-the-art Bi(Te, Se)-based films. Moreover, the estimated average zT value of the film is as high as ∼0.81. We then constructed thin-film TE devices by using the above oriented Bi(Te, Se) films, and the maximum output power density of the device can reach up to ∼30.1 W/m2 under the temperature difference of 40 K. Predictably, the outstanding average TE performance of the highly oriented Bi(Te, Se) thin films will have an excellent panorama of applications in semiconductor cooling and power generation.