Photoelectric Applications Research Articles

Perspective of environmentally friendly antimony selenide-based solar cell

Antimony selenide has been intensively investigated as an interesting alternative for solar cell absorbers due to its excellent physical properties. Owing to the remarkable advancements in the last several decades, chemical and physics methods have improved the power conversion efficiency of antimony selenide solar cells by over 10%, almost at the level needed for industrial applications. In this perspective, we have outlined the issues and challenges these antimony chalcogenides face in photoelectric applications. We have proposed some feasible suggestions for improving its performance and applications in solar cells and other optoelectronic devices.

Stable Xanthene Radicals and Their Heavy Chalcogen Analogues Showing Tunable Doublet Emission from Green to Near-infrared.

Organic luminescent radicals, unlike traditional closed-shell fluorescent emitters, exhibit distinct luminescence mechanisms, offering promising potential for optoelectronic devices. To date, stable luminescent radicals have predominantly been confined to polychlorinated triphenylmethyl radicals, underscoring the need for new platforms to expand their emission spectra. In this study, we report the synthesis of stable 9-aryl-substituted xanthene radicals and their heavy chalcogen analogues (1a-c and 2a-c), which exhibited excellent chemical stability and emission ranging from green to near-infrared (527~714 nm). Notably, the selenium-substituted radical (1c) demonstrates a significantly enhanced photoluminescence quantum yield of 41% when doped into its precursor solid. Additionally, the introduction of methoxyphenyl groups has largely enhanced the stability of the radical, showcasing an excellent photostability with the longest half-life of around 1792 h. The high internal quantum efficiency of up to 81% was further validated in organic light-emitting diode. This study introduces a novel class of stable carbon-centered radicals with high tunability and functionality for photoelectric applications.

Stable Xanthene Radicals and Their Heavy Chalcogen Analogues Showing Tunable Doublet Emission from Green to Near‐infrared

Organic luminescent radicals, unlike traditional closed‐shell fluorescent emitters, exhibit distinct luminescence mechanisms, offering promising potential for optoelectronic devices. To date, stable luminescent radicals have predominantly been confined to polychlorinated triphenylmethyl radicals, underscoring the need for new platforms to expand their emission spectra. In this study, we report the synthesis of stable 9‐aryl‐substituted xanthene radicals and their heavy chalcogen analogues (1a‐c and 2a‐c), which exhibited excellent chemical stability and emission ranging from green to near‐infrared (527~714 nm). Notably, the selenium‐substituted radical (1c) demonstrates a significantly enhanced photoluminescence quantum yield of 41% when doped into its precursor solid. Additionally, the introduction of methoxyphenyl groups has largely enhanced the stability of the radical, showcasing an excellent photostability with the longest half‐life of around 1792 h. The high internal quantum efficiency of up to 81% was further validated in organic light‐emitting diode. This study introduces a novel class of stable carbon‐centered radicals with high tunability and functionality for photoelectric applications.

Dual-shell protection enables highly efficient and stable all-inorganic perovskite composites for light-emitting-diodes

Lead-halide perovskite nanocrystals (NCs) present superior photoelectric properties, but the poor stability seriously hinders their practical application. The encapsulation of perovskite NCs inside mesoporous silica (m-SiO2) matrix is considered as one of the most feasible pathways to improve the stability of NCs. However, the challenges of loose encapsulation structure, aggregation of particles, high energy consumption during the preparation of CsPbX3@m-SiO2 composites have not yet been overcome, which throw a shadow over the large-scale commercial applications. Here, we present a dual-shell encapsulation strategy that enables the formation of highly emissive CsPbBr3@m-SiO2@SiO2 composites, achieving an exceptional photoluminescence quantum yield (PLQY) of 97.37 %. The reaction parameters for the preparation of composites are meticulous investigated. The CsPbBr3 NCs can be well formed inside the pores of m-SiO2 as the m-SiO2 is introduced into the precursor solution. The secondary SiO2 shells can effectively seal the open pores of m-SiO2. As a result, the as-prepared CsPbBr3@m-SiO2@SiO2 composites present excellent stability, in which the composites can maintain 93.16 % of initial intensity after storage for 84 days. Besides, a series of CsPbX3@m-SiO2@SiO2 composites with tunable emission wavelength in the range of 428.6–630.6 nm are prepared through facile designing the halide ratios of precursor solution, which present a wide color gamut (148.48 % of the National Television Standards Committee). In addition, a white light-emitting diode (LED) is fabricated by combining CsPbBr3@m-SiO2@SiO2 composites and K2SiF6:Mn4+ phosphors with a 455 nm LED chip, which exhibits good photoelectric performances. This facile low-temperature dual-shell encapsulation strategy reported here provides a new pathway for preparing high-performance perovskite composites, facilitating their practical photoelectric application.

Evaluating Sulfur as a P‐Type Dopant in Cu3N Using Ab Initio Methods

Copper nitride (Cu3N) is an environmentally friendly semiconducting material with bipolar doping capability and is of interest to various applications. As deposited Cu3N films have inherent n‐type conductivity, further controllable n‐type doping is possible by introducing metal impurities. First‐principles methods based on density functional theory and beyond have been employed to study the p‐type doping behavior of sulfur atoms in Cu3N. The structural, electronic, optical, and thermal properties of pure Cu3N and sulfur‐doped Cu3N are computed for single and 3 × 3 × 3 supercells. Sulfur doping causes a shift from intrinsic n‐type to p‐type behavior. This study confirms that sulfur atoms in sulfur‐doped copper nitride preferentially occupy interstitial positions over nitrogen substitution, face‐centered, or copper substitution sites. Due to this change and an increased lattice constant, Cu3N becomes a softer material with a larger bandgap in the single‐cell alloy. Doped Cu3N supercell results show significant changes in optical properties appropriate for solar and other photoelectric applications. Cu3N:S exhibits remarkable enhancements in power factor and thermal and electrical conductivity, indicating potentially better performance in thermoelectric applications. The dielectric constant and absorption coefficient also significantly change with the incorporation of sulfur into Cu3N.

Ultrahigh-performance photodetectors based on low-dimensional Cs2AgBiBr6/CdS heterojunction

Lead-free double perovskite Cs2AgBiBr6 has garnered increasing attention in photoelectric applications owing to its good stability and excellent photoelectric properties. However, the poor carrier transport in Cs2AgBiBr6 thin films constraints their further application in photodetection. To overcome this issue, we have developed an innovative low-dimensional Cs2AgBiBr6/CdS heterojunction photodetector with substantially improved performance. The device achieved a high responsivity of 6.66 × 103 A/W, an outstanding specific detectivity of 2.10 × 1014 Jones, and an impressive external quantum efficiency of 1.88 × 106 %. Additionally, the on/off current ratio of the heterojunction device reached an impressive 6.18 × 107. These key parameters are significantly better than those of most previously reported Cs2AgBiBr6-based photodetectors. Furthermore, scanning photocurrent mapping and band arrangement analysis were performed to elucidate the mechanism of photocurrent generation and transport in the low-dimensional Cs2AgBiBr6/CdS heterojunction photodetectors. This study highlights the outstanding performance of Cs2AgBiBr6/CdS heterojunction and provides a simple and effective strategy for developing high-performance Cs2AgBiBr6-based photodetectors.

Pressure-Induced Structural Transition and Enhanced Photoelectric Properties of Tm2S3

Abstract Rare earth sesquisulfides have drawn growing attention in photoelectric applications because of their excellent electronic and photoelectric properties upon compression. We investigate the structural, electrical, and photoelectric properties of Tm2S3 under high pressure through electrical impedance, UV-vis absorption, Raman spectroscopy, x-ray diffraction, and photoelectric measurements. It is found that δ-Tm2S3 transforms into high-pressure α-phase around 5 GPa, accompanied by a substantial reduction in atomic distance, bandgap, and resistivity. Consequently, the photocurrent density and responsivity of Tm2S3 exhibit dramatic increase behavior, achieving five orders of magnitude enhancement in α-phase compared with the initial δ-Tm2S3. Moreover, α-phase maintains a high photocurrent responsivity of three orders of magnitude after unloading. This work demonstrates significant enhancement of the photoelectric properties of Tm2S3 by applying pressure, which paves the way for improving the performance of future photoelectric devices.

Multicolor and multimode luminescent lanthanide-doped Cs2NaInCl6:Sb3+ from visible to near infrared for versatile applications

Double halide perovskites have shown admirable potential in promising optoelectronic applications due to simple synthesis, good stability and high structural tolerance. However, the poor optical properties caused by the parity-forbidden transitions posts a stringent limitation on their potential applications. Herein, we dope the lanthanide (Ln3+) ions with abundant energy levels into the Cs2NaInCl6:Sb3+ single crystals, which not only achieve multicolor visible emissions spectra from blue to red light, but also expand to the near infrared region from 800 to 1900 nm. In addition, the phosphors enable the multimode emissions with the up-conversion and down-conversion photoluminescence. Intriguingly, the excitation source, and the excitation light intensity also endow the multicolor emissions. Thus, combining with the multicolor and multimode luminescent properties, Cs2NaInCl6:Sb3+/Ln3+ could be applied to night vision imaging, substance detection, optical thermometry, white-light-emitting diodes (WLEDs) and anti-counterfeiting. The maximum value of relative temperature sensitivity reaches as high as 1.207 % K−1, which is relatively higher than those of most metal halide perovskites. Moreover, the single-source WLED displays Commission Internationale de L'Eclairage color coordinates (0.32, 0.31), a correlated color temperature of 6673 K, and color rendering index of 81.7. These results demonstrate the potential applications in the multifunctional photoelectric applications.

Facile synthesis, multimode and tunable luminescence, and multifunctional applications of rare earth ions activated lead-free double perovskite crystals

Lead-free double perovskites have gained recognition as top luminescent materials due to their environmental friendliness, high chemical stability, structural adjustability, and excellent photoelectric properties. However, the poor modulation of emission restricts their applications, and it is highly desirable to explore stable and efficient double perovskites with multimode luminescence and adjustable spectra for multifunctional photoelectric applications. Herein, the rare earth ions Ln3+ (Er3+ and Ho3+) doped Cs2NaYCl6:Sb3+ crystals were synthesized by a simple solvothermal route. The X-ray diffraction pattern (XRD), energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and elemental mapping images demonstrate that the Sb3+, Er3+, and Ho3+ ions have been homogeneously incorporated into the Cs2NaYCl6 crystals. As anticipated, the emission spectra of Cs2NaYCl6:Sb3+/Ln3+ are composed of two bands. One broad blue band derives from self-trapped exciton (STE) in [SbCl6]3− octahedra while another group of emission peaks stems from the f-f transitions of Ln3+ ions. The emission colors of Cs2NaYCl6:Sb3+/Ln3+ phosphors can be tuned in a wide range by modulating the doping concentrations of Ln3+ ions. The efficient energy transfer from STE to Ln3+ is the key point to achieving the efficient and tunable emissions Cs2NaYCl6:Sb3+/Ln3+ samples. Interestingly, Cs2NaYCl6:Sb3+/Ln3+ can also exhibit characteristic up-conversion luminescence of Ln3+ under near-infrared (NIR) excitation besides the down-conversion luminescence, revealing that the materials may have potential applicability in multimode anti-counterfeiting and information encryption applications. Furthermore, the light emitting diodes (LEDs) assembled by Cs2NaYCl6:Sb3+ and Cs2NaYCl6:Sb3+/Ln3+ phosphors display dazzling blue, green, and red emissions under a forward bias current, which indicates that the as-obtained double perovskites materials may have great potential in solid-state lighting and optoelectronic devices.

Recent Advances in the A‐Site Cation Engineering of Lead Halide Perovskites

AbstractLead halide perovskite (LHP) have gained considerable research attention for their numerous photoelectric applications attributed to their ease of processability and distinctive photoelectric properties. A‐site cation engineering provides an effective solution to optimize the bandgap further, enhance stability, and improve the photoelectric properties of LHP materials. In this review, an in‐depth examination of the progress achieved in the field of A‐site cation engineering on the structure, properties, synthesis methods, and photoelectric applications of LHP is presented. It is discussed how A‐site cations can change the crystal structure and improve the crystal quality, and how the A‐site cation regulates the bandgap, enhances stability, and promotes effective charge transport. Further, synthesis strategy is presented to regulate the A‐site cation. Subsequently, the applications of A‐site cation‐regulated LHP materials in solar cells, light‐emitting diodes, photodetectors, and lasers are introduced. Finally, challenges that must be overcome to further improve the properties and stability of LHP materials via A‐site cation engineering are highlighted.

Graphene-PbS Quantum Dot Heterostructure for Broadband Photodetector with Enhanced Sensitivity.

Photodetectors converting light into electrical signals are crucial in various applications. The pursuit of high-performance photodetectors with high sensitivity and broad spectral range simultaneously has always been challenging in conventional semiconductor materials. Graphene, with its zero bandgap and high electron mobility, is an attractive candidate, but its low light absorption coefficient restricts its practical application in light detection. Integrating graphene with light-absorbing materials like PbS quantum dots (QDs) can potentially enhance its photodetection capabilities. Here, this work presents a broadband photodetector with enhanced sensitivity based on a graphene-PbS QD heterostructure. The device leverages the high carrier mobility of graphene and the strong light absorption of PbS QDs, achieving a wide detection range from ultraviolet to near-infrared. Employing a simple spinning method, the heterostructure demonstrates ultrahigh responsivity up to the order of 107 A/W and a specific detectivity on the order of 1013 Jones, showcasing significant potential for photoelectric applications.

Regulating ligand length to improve the PL QY and stability of CsPbCl0.9Br2.1 nanocrystals for LEDs and photoelectric applications

Perovskite luminescent materials have been extensively investigated due to their comprehensive applications for full-color display, lighting, and communication. However, the development of blue-emissive perovskites has seriously lagged behind that of green and red counterparts, primarily because of their low photoluminescence quantum yield (PL QY) and poor stability. Here, we prepared blue-emissive CsPbCl0.9Br2.1 perovskite nanocrystals (PeNCs) and enhanced their QY from 61.3 % to 90.4 % by regulating the chain lengths of ligands. Post-treated PeNCs also exhibit good stability, their PL intensity is maintained at about 90 % after storage at ambient conditions for 10 days. The exciton dynamics results obtained from time-resolved fluorescence spectra and transient absorption spectra show that dodecyldimethylammonium bromide (DDAB), featuring double 12-hydrocarbon chains, is more capable of passivating surface defects and inhibiting non-radiative composites than the other double 8- or double 16-carbon chain ligands, which greatly improved the probability and rate of radiative recombination. Subsequently, the mechanism of ligand chain length regulation on the PL properties and stability of PeNCs was analyzed in terms of ligand-NC surface interaction, ligand polarity, hydrophobicity, and spatial effects. Furthermore, the device based on DDAB-CsPbCl0.9Br2.1 demonstrated stable EL and long operation lifetime, indicating its significant potential as an efficient blue emitter for backlighting in display technologies.

Facile Fabrication of Highly Crystallized, Air‐Stable, and Flexible Perovskite Micromesh Film Photodetector

AbstractPerovskite materials such as organic‐inorganic MAPbX3 (X = Cl, I, Br) have attracted broad interests in photoelectric applications, such as image sensors and photovoltaics. Here, a facile and general approach, called soft‐print solvent‐assisted evaporation crystallization (SSEC) is reported, for fabrication of highly crystallized, air‐stable, and flexible perovskite micromesh films, including organic–inorganic (MAPbX3) and inorganic (CsPbX3) perovskite. Scanning and transmission electron microscopy (SEM/TEM) characterization reveals their high crystallinity without obvious grain boundaries. The photodetectors constructed based on MAPbI3 micromesh films exhibit a typical responsivity of ≈352 A W−1 and detectivity of ≈5.7 × 1013 Jones (at 650 nm in wavelength). The MAPbI3 micromesh film also shows good mechanical stability when bended at different bending radius, and after 800 bending cycles, they still exhibit highly reproducible photocurrent and on/off switching ratios. Furthermore, they are also air‐stable that they can survive for >20 days in high humid environments (65–75%) with <10% reduction in photocurrent. This work provides a facile and scalable approach for fabrication of highly crystallized, stable, and flexible perovskite micromesh films for a variety of optoelectronic applications with improved performance and durability.

Experimental investigation on magnetorheological shear thickening polishing characteristics for SiC substrate

Silicon carbide (SiC) substrates are widely used in semiconductor and photoelectric applications due to excellent electrical and chemical properties. However, due to its inherent hard-brittle properties and chemical inertness, traditional polishing processes are facing great challenges to obtain excellent surface and subsurface quality for the SiC substrates. In this work, a novel polishing process i.e. magnetorheological shear thickening polishing (MRSTP) was proposed to explore the feasibility for the polishing of the SiC substrates. The MRSTP experiments were conducted using multiple magnetic-pole-coupled tools. The magnetic field characteristics of the polishing area were investigated via finite element simulation and actual measurements. The magnetic-pole-coupled tool was capable of generating high magnetic induction strength in the polishing area. The MRSTP medium was designed and prepared. The media were formed magnetic brushes by the excited magnetic field. The MRSTP experiments were conducted to investigate the effects of processing parameters on the polished surface roughness. The optimum process parameters were determined as the spindle rotational speed of 700 rpm, the feed rate of 600 mm/min, the work gap of 0.5 mm and MRSTP media CIPs particle size of 100 μm. The surface roughness of the workpieces was improved from initial 1.414 μm to 27.6 nm. It is verified that the MRSTP is the feasible ultraprecision polishing process for the SiC substrates.

Sulfur-doped g-C3N4/GaN n-n heterojunction for high performance low-power blue-ultraviolet photodetector with ultra-high on/off ratio and detectivity

Polymeric graphitic carbon nitride (g-C3N4) shares a structural similarity to graphene, yet it possesses a distinctive electronic band structure, rendering it promising for photoelectric applications. However, g-C3N4 faces inherent limitations such as inadequate crystalline quality, limited conductivity, and a short lifespan of photogenerated charge carriers, all of which impede the photoelectric conversion efficiency. In this work, we introduce a two-step thermal vapor condensation method for depositing compact, crack-free sulfur-doped g-C3N4 thin films. The doped thin films exhibit reduced interlayer spacing, which leads to improved conductivity and charge transfer capabilities. These processes culminate in the creation of sulfur-doped g-C3N4/GaN thin film heterojunction blue-ultraviolet photodetectors with remarkable photodetection performance, including an ultrahigh on/off ratio of 7.3 × 107 and specific detectivity of 2.06 × 1014 Jones under a low bias of −0.4 V. Moreover, it is found that the n-n heterojunction undergoes a transition from photodiode to photoconduction behavior, attributed to the photoinduced electron trapping effects by sulfur-doped sites, which outcomes a notable gain with the responsivity as high as 581 mA/W. These findings underscore the vast potential of high-quality sulfur-doped g-C3N4 thin films for photoelectric applications.

Sandwiched WS2/MoTe2/WS2 Heterostructure with a Completely Depleted Interlayer for a Photodetector with Outstanding Detectivity.

Photodetectors based on two-dimensional van der Waals (2D vdW) heterostructures with high detectivity and rapid response have emerged as promising candidates for next-generation imaging applications. However, the practical application of currently studied 2D vdW heterostructures faces challenges related to insufficient light absorption and inadequate separation of photocarriers. To address these challenges, we present a sandwiched WS2/MoTe2/WS2 heterostructure with a completely depleted interlayer, integrated on a mirror electrode, for a highly efficient photodetector. This well-designed structure enhances light-matter interactions while facilitating effective separation and rapid collection of photocarriers. The resulting photodetector exhibits a broadband photoresponse spanning from deep ultraviolet to near-infrared wavelengths. When operated in self-powered mode, the device demonstrates an exceptional response speed of 22/34 μs, along with an impressive detectivity of 8.27 × 1010 Jones under 635 nm illumination. Additionally, by applying a bias voltage of -1 V, the detectivity can be further increased to 1.49 × 1012 Jones, while still maintaining a rapid response speed of 180/190 μs. Leveraging these outstanding performance metrics, high-resolution visible-near-infrared light imaging has been successfully demonstrated using this device. Our findings provide valuable insights into the optimization of device architecture for diverse photoelectric applications.

Fast and broadband spatial-photoresistance modulation in graphene–silicon heterojunctions

Abstract Different types of devices with modulable resistance are attractive for the significant potential applications such as sensors, information storage, computation, etc. Although extensive research has been reported on resistance effects, there is still a need for exploring new mechanisms that offer advantages of low power consumption, high sensitivity, and long-term stability. Here, we report a graphene–Si based spatial-dependence photo-rheostat (SDPR), which enables bipolar resistance modulation in the range of 5 mm with a resistance sensitivity exceeding 1,000 Ω/mm at operating wavelengths from visible to near infrared band (1,550 nm). Especially, at ultra-low energy consumption, the device can achieve modulation of even 5 orders of magnitude of resistance and response speed up to 10 kHz. A theoretical model based on carrier dynamics is established to reveal the diffusion and drift of carriers as a mechanism explaining such experimental phenomenon. This work provides a new avenue to modulate resistance at low power consumption as novel opto-potentiometers in various photoelectric applications.

Small electron polarons bound to interstitial tantalum defects in lithium tantalate

The absorption features of optically generated, short-lived small bound electron polarons are inspected in congruent lithium tantalate, LiTaO3 (LT), in order to address the question whether it is possible to localize electrons at interstitial Ta V :V Li defect pairs by strong, short-range electron–phonon coupling. Solid-state photoabsorption spectroscopy under light exposure and density functional theory are used for an experimental and theoretical access to the spectral features of small bound polaron states and to calculate the binding energies of the small bound Ta Li4+ (antisite) and Ta V4+ :V Li (interstitial site) electron polarons. As a result, two energetically well separated ( ΔE≈0.5 eV) absorption features with a distinct dependence on the probe light polarization and peaking at 1.6 eV and 2.1 eV are discovered. We contrast our results to the interpretation of a single small bound Ta Li4+ electron state with strong anisotropy of the lattice distortion and discuss the optical generation of interstitial Ta V4+ :V Li small polarons in the framework of optical gating of Ta V4+ :Ta Ta4+ bipolarons. We can conclude that the appearance of carrier localization at Ta V :V Li must be considered as additional intermediate state for the 3D hopping transport mechanisms at room temperature in addition to Ta Li , as well, and, thus, impacts a variety of optical, photoelectrical and electrical applications of LT in nonlinear photonics. Furthermore, it is envisaged that LT represents a promising model system for the further examination of the small-polaron based photogalvanic effect in polar oxides with the unique feature of two, energetically well separated small polaron states.

2D Growth of BiSCl as Anisotropic Photodetector with Ultrahigh Responsivity and Detectivity

AbstractBiSCl, which shares the anisotropic chain‐like lattice configuration with the BiVXVIYVII (XS, Se; YCl, Br, I) family displays high photoelectric conversion efficiency in the UV–vis wavelength region. The current difficulty in 2D growth restricts the investigation of device performance and further integration. Herein, an epitaxial growth strategy for 2D BiSCl is proposed based on the principle of sharing a chloridion layer at the BiSCl/BiOCl interface. The interfacial atomic arrangement is carefully revealed using atomic resolved AC‐TEM(Spherical Aberration High Transmission Electron Microscope) and demonstrated by calculations based on density functional theory. Benefiting from its compatibility with PS‐assisted large‐scale transfer technology, the photoelectric performance is evaluated by constructing a standard symmetrical photoconductor and Graphene‐BiSCl Schottky junction device. High responsivity (1.71 × 104 A W−1) and detectivity (5.9 × 1016. Jones) are achieved at 405 nm, and robustness is shown in a broadband spectrum, which manifested prominent anisotropic photoelectric behavior and great potential in weak‐light detection. These results elucidate the photoelectric applications of BiSCl semiconductors and the structural design of the BiVXVIYVII family.

Near‐Infrared and Cyan Dual‐Band Emission Copper Iodide Based Halides with [Cu6I9]3− Cluster

AbstractThe luminescence property of various compounds is developed in the photoelectric applications field, while the near‐infrared (NIR) dual‐band emission of compounds is extremely challenging. Herein, 0D Cu(I)‐based organic–inorganic module (ETA)3Cu6I9 is synthesized to achieve NIR and cyan dual‐band emission in metal halide systems. Density functional theory (DFT) calculations combined with comprehensive spectroscopic data reveal its emission mechanism. Under the excitation at 371 nm, (ETA)3Cu6I9 shows the broadband NIR emission peaking at 775 nm with a large wavelength, attributed to the triple‐cluster‐center (3CC) transition. Meanwhile, under 286 nm excitation, (ETA)3Cu6I9 shows a bright cyan emission peaking at 490 nm, attributed to the metal‐to‐ligand charge transfer (MLCT) or halide‐to‐ligand charge transfer (XLCT) transitions. Moreover, (ETA)3Cu6I9 presents relatively superior thermal and air stability. Benefiting from the good stability of (ETA)3Cu6I9, the as‐fabricated NIR‐LED device demonstrates great potential in biological imaging and night vision. This study opens up a new way for designing new non‐toxic NIR and cyan dual‐band emission materials, which guides to synthesize new materials in metal halide field.