Optical Response Research Articles

Large Optical Nonlinearity Enhancement and All‐Optical Logic Gate Implementation in Silver‐Modified Violet Phosphorus

AbstractAs the most stable allotrope of phosphorus, violet phosphorus (VP) has attracted extensive research in the field of all‐optical modulation due to its excellent broadband spatial self‐phase modulation (SSPM) effect. To better exploit the great potential of VP in nonlinear photonics devices, this work explores chemical doping method to artificially enhance the nonlinear optical response of VP. Herein, silver‐modified few‐layer VP (Ag‐VP) is constructed for SSPM experiments. In comparison to pristine VP, a significantly improved third‐order nonlinear susceptibility (χ(3)) and nonlinear optical response for Ag‐VP is obtained in visible light band, and the enhancement ratio increases with the increase of wavelength. Moreover, the excitation threshold of SSPM effect is also significantly reduced, with a reduction ratio up to 3.61. The enhanced nonlinear optical response is attributed to the improved light–matter interaction induced by impurity energy levels. By taking advantage of the outstanding SSPM effect of Ag‐VP, an all‐optical logic gate is designed to demonstrate “OR” logical information transmission. This work provides a new avenue for the design and application of energy‐saving and tunable nonlinear photonic devices in the future.

Investigation of optical and thermoelectric characteristics of novel zintl-phase alloys CaZn2X2 (X = P, As, Sb) for green energy applications

Abstract This study examines the photovoltaic and thermoelectric response of calcium-based novel Zintl-phase alloys CaZn2X2 (X = P, As, Sb). The structural, optoelectronics, and transport features of Zintl CaZn2X2 (X = P, As, Sb) compounds have been analyzed using the full potential linearized augmented plane wave (FPLAPW) technique. Investigations on formation energy and phonon dispersion have confirmed the formation and dynamical stabilities. These compounds exhibit a semiconductor behavior, as their predicted bandgap values: 1.76 eV for CaZn2P2, 1.14 eV for CaZn2As2, and 0.32 eV for CaZn2Sb2. By investigating the optical properties, we have discovered their potential applicability in optoelectronic and photovoltaic devices, as evidenced by the optical response of these phases. The traditional Boltzmann transport theory has assessed transport characteristics against temperature and chemical potential. Significantly higher values of the Seebeck coefficient are achieved at room and elevated temperatures. Moreover, the power factor demonstrates a linear relationship with rising temperature. The remarkable optoelectronic properties and exceptional power factor values suggest that these materials are suitable for deployment in photovoltaic and transport devices.

Giant Modulation of Second-Harmonic Generation in CuInP2S6 by Interfacing with MoS2 Atomic Layers.

Probing and manipulating the intriguing nonlinear optical responses in van der Waals (vdW) ferroelectrics offer opportunities for their applications in nanophotonics. Here, we report the observation of giant and tunable second-harmonic generation (SHG) in ferroelectric CuInP2S6 (CIPS) and CIPS/MoS2 heterostructures. The results show that CIPS, ranging from multilayer to bulk-like samples, all exhibit strong SHG with giant anisotropy. The SHG anisotropy is attributed to the local strain along the a-axis that naturally exists in CIPS, as evidenced by piezoresponse force microscopy measurement. We further realized the strong modulation of SHG in CIPS by interfacing with monolayer MoS2. A combination of polarization, temperature, and thickness-dependent SHG and photoluminescence analyses shows that the nonlinear optical signal control in CIPS/MoS2 heterostructures is unrelated to the polar symmetry of CIPS and MoS2 but is driven by light absorption-mediated interfacial coupling. Our study provides a material platform based on vdW ferroelectric heterostructures for achieving dynamic control of nonlinear optical responses, which shows great potential applications in modern nanophotonics.

Multicolor Gold Clusterzyme-Enabled Construction of Ratiometric Fluorescent Sensor Array for Visual Biosensing.

The simultaneous detection of multiple bioanalytes with similar structures has been a long-standing challenge for biological research and disease diagnosis. Bioreceptor-inspired sensor arrays provide an attractive and competitive solution for addressing this challenge, but applying this technique to biosensing in practical application scenarios is complicated by many factors such as the lack of robust probes, interference from the biological matrix, and difficulty for on-site analysis. In this work, by taking advantage of the intrinsic fluorescence and enzyme-mimic properties of gold nanoclusters (AuNCs), we report the design of an innovative ratiometric sensor array toward enhanced fluorescent visual biosensing. With biologically important phosphates as an example, we show that the present fluorescent clusterzyme-based ratiometric sensor array could effectively discriminate and detect eight types of phosphates. In particular, AuNCs with three different emission colors (blue, green, and red) and good peroxidase-mimic properties were employed as the sensing units, and the presence of phosphates affected both the intrinsic fluorescence and the enzymatic activity of these AuNCs, yielding distinct optical responses in a ratiometric manner. Moreover, a portable sensor array was established by further integrating these fluorescent clusterzymes into a hydrogel matrix, which could visually identify different phosphates based on their distinct fluorescence color changes. Consequently, the point-of-care diagnosis of urinary tract infections at different levels was achieved by analyzing urinary microbial ATP via the present strategy. This study illustrates the great potential of clusterzyme-based fluorescent sensor arrays as a promising biosensing platform for disease diagnosis.

Water-Vapor-Triggered Dual-Mode Optical Responses in Rare-Earth-Doped Hollow Nanospheres.

Multimode responsive optical materials are garnering ever-increasing attention due to their diverse applications. This work showcases a film assembled with rare-earth-doped CaF2 hollow nanospheres that exhibit water-vapor-triggered dual-mode optical responses. Upon exposure to flowing water vapor, the film rapidly (less than 1.5 s for a 7.7 μm thickness) transitions to a transparent state and simultaneously undergoes a sharp decrease in the photoluminescence intensity. Both of these changes fully reverse upon water evaporation, demonstrating an impressive reversibility over at least 200 cycles. The water-vapor-induced dual-mode responses are attributed to the altered incident light propagation path stemming from the similar refractive indices between CaF2 and water, coupled with the water-induced energy loss of the rare-earth ions. The fabrication of encryption patterns displaying separate signals in multiple channels, as well as the demonstration of noncontact sensing for water vapor distribution, underscore the promising application potential of this dual-mode responsive system.

Germanium-incorporated Si-Ge-Si heterojunction phototransistors for a high-limit of detection and wide linear dynamic range near-infrared light detection

This paper investigates overcoming the limitations of conventional silicon (Si) bipolar junction transistors (BJTs) for near-infrared (NIR) light detection. Silicon BJTs have inherent limitations in the NIR region due to silicon’s bandgap. To address this, the paper proposes high-performance silicon-germanium-silicon (Si-Ge-Si) heterojunction bipolar phototransistors (HPTs). The key innovation is introducing a thin germanium (Ge) layer at the base-collector junction and engineering its doping concentration. This Ge layer extends the BJT phototransistor’s optical response into the NIR region by enhancing optical absorption. The paper analyses the performance of the HPTs, demonstrating linear photoresponsivity of 432 mA/W over a wide optical power range, leading to an exceptional linear dynamic range of 159 dB and a very low dark current, which produces a limit of detection of -99.64 dBm. Additionally, the device exhibits a large photo-to-dark current ratio of 2.16 ×107 (at optical power of 5 µW) and a fast response time of 11.35 ps to modulated NIR optical signals within the linear dynamic range. This research paves the way for high-performance CMOS-compatible NIR phototransistors using Si-Ge-Si heterostructures.

Unleashing the nonlinear optical response of layered vanadium diselenide towards the deep mid-infrared regime

Broadband nonlinear optical materials towards the deep mid-infrared regime are highly required in medical diagnostics, environmental pollution monitoring, etc. Here, we report the ultra-broadband nonlinear optical absorption behavior of the layered vanadium diselenide (VSe2) towards deep mid-infrared regime experimentally. The layered VSe2 prepared by the liquid-phase exfoliation method exhibits broadband and wavelength-dependent nonlinear saturable absorption and a large modulation depth of over 8% in the 3-10 µm spectral range. By utilizing the layered VSe2 for optical modulation, stable nanosecond pulse with a low Q-switched threshold has been delivered successfully from an erbium-doped ZBLAN fiber laser. The experimental findings can deepen the understanding of the nonlinear optical response of the transition metal dichalcogenides towards the deep mid-infrared regime, and may make inroads for the advancement of mid-IR optoelectronic devices.

Increased Formation of Trions and Charged Biexcitons by Above-Gap Excitation in Single-layer WSe2.

Two-dimensional semiconductors exhibit pronounced many-body effects and intense optical responses due to strong Coulombic interactions. Consequently, subtle differences in photoexcitation conditions can strongly influence how the material dissipates energy during thermalization. Here, using multiple excitation spectroscopies, we show that a distinct thermalization pathway emerges at elevated excitation energies, enhancing the formation of trions and charged biexcitons in single-layer WSe2 by up to 2× and 5× , respectively. Power- and temperature-dependent measurements lend insights into the origin of the enhancement. These observations underscore the complexity of excited state relaxation in monolayer semiconductors, provide insights for the continued development of carrier thermalization models, and highlight the potential to precisely control excitonic yields and probe nonequilibrium dynamics in 2D semiconductors.

First-Principles Investigation of Structural, Electronic, Optical, Elastic, and Thermoelectric Properties of Cubic Francifluorite Perovskites FrXF3 (X = Si, Ge, and Sn) for Optoelectronic and Thermoelectric Device Applications

Abstract This study presents the results of first-principles calculations based on Density Functional Theory (DFT) implemented in the Wien2k code, investigating the properties of FrXF3 compounds where B represents Si, Ge, and Sn. Various exchange-correlation functionals, including Generalized Gradient Approximation (GGA) with Perdew-Burke-Ernzerhof (GGA-PBE), Perdew-Burke-Ernzerhof revised for Solids (GGA-PBEsol), Wu-Cohen exchange (GGA-WC), and Modified Becke-Johnson potential (TB-mBJ), were employed to comprehensively analyze the structural, electronic, optical, elastic, and thermoelectric characteristics of these compounds. The analysis of band structures and density of states revealed that all three compounds exhibit semiconducting behavior with direct band gaps, and the band gaps decrease as we move from Si to Sn. The calculated optical properties indicate strong optical responses in the visible to ultraviolet energy range, suggesting potential applications in optoelectronics. Furthermore, the study evaluated the thermoelectric parameters, including thermal and electrical conductivity, power factor, Seebeck coefficient, and figure of merit. The results demonstrate that the FrXF3 compounds possess remarkable thermoelectric potential, indicating their suitability for thermoelectric applications. Overall, this comprehensive investigation provides valuable insights into the structural, electronic, optical, elastic, and thermoelectric properties of FrXF3 compounds, highlighting their potential for various technological applications, particularly in the field of optoelectronics and thermoelectric devices.

Facile Access to Phosphorus Ylide-fused Heteroarenes Possessing Tunable Optoelectronic Properties and High Nonlinear Optical Performances.

We report here a novel family of ylidic P-heteroarenes (P1-P6), structurally featuring unique phosphonium cyclopentadienylide (P-Cp)-fused π-skeletons and synthetically prepared via an unexpected one-pot [2+3]/[3+3] phospha-annulation reaction. While the facile and modular synthesis allows the fine-tuning of their optical absorptions and redox properties, single-crystallographic and theoretical analysis of these P-heteroarenes further reveal that the fusion of P-Cp moiety leads to substantial intramolecular charge-separated features with high ylidic character values of up to 84 %. Benefitted from such dipolar structures, these P-heteroarenes not only allows stepwise electrophilic substitution reaction for further structural π-expansions, but also exhibit excellent nonlinear optical (NLO) responses and optical limiting (OL) performances comparable to or exceed those of C60. As a model compound, the persistent radical-anion salt of P5a was also prepared through chemical reduction, thus offering valuable insights into the electronic structures of reduced P-ylidic species. Our work not only established a highly efficient synthetic method toward new P-heteroarenes, but also provide fundamental understanding of those fused-ring ylidic P-heterocycles with promising NLO/OL applications.

Thermo-optical analysis of a nanocone based solar absorber for thermophotovoltaic applications

Abstract We investigate the optical and thermal response of a 2D photonic crystal absorber composed of tungsten nanocones, with complete and truncated shapes used in a solar thermophotovoltaic (STPV) system. We explain how the absorption and temperature of the structure are affected by the presence of a protection layer, lens and an emitter. The total efficiency and contribution of thermal emittance of complete nanocone arrays are compared with truncated absorbers. Based on our results, the efficiency of a non-protected nanocone hits 67% at 400 sunlight and the temperature reaches 1350 K. By adding a silica layer on the absorber, the efficiency slightly reduces to 61%. In addition, we observed a reduction in the efficiency of all studied absorbers at higher sunlight concentration factors. Our results also indicate that the thickness of a silica layer on the tungsten substrate does not have a noticeable change in the efficiency. Finally, the deformation of the structure due to surface diffusion is studied. This study paves the way toward a multi-physical analysis of photonic crystal absorbers in STPV systems.

MEMS-tunable topological bilayer metasurfaces for reconfigurable dual-state phase control

Tunable optical metasurfaces (MSs) have demonstrated exceptional capabilities in actively manipulating light fields. However, most existing tunable MSs are limited to controlling only one functionality. Here, by combining a MEMS mirror with a plasmonic bilayer MS (BMS), we develop an electrically driven MEMS-BMS platform enabling complete reflection phase transformation and switching between two encoded functionalities by actuating the MEMS mirror. This capability stems from different optical responses of each MS layer at distinct MEMS-BMS separations, due to evolving topological singularities in a defined parameter space. With this tunable topological MEMS-BMS platform, we demonstrate polarization-independent MEMS-BMS for reconfigurable diffraction gratings, achieving ∼25% efficiency, ∼0.75 contrast at 850-nm wavelength, and fast response (∼5µs). The MEMS-BMS arrangement for generating vortex beams with switchable topological charges of ±1 is also demonstrated, evidenced by distinct near- and far-field interferograms. Our work expands the scope of tunable MSs by exploiting dynamic topological phases in the MEMS-BMS arrangement, paving the way for multifunctional tunable meta-optics.

Origin of Oxidation Variations in Ambient-Stable β-InSe.

Understanding and controlling the oxidation of layered materials remain critical issues in the final stages of their practical application in devices. Layered materials achieve a band gap by removing inversion symmetry. However, the oxidation process becomes complex, and the oxidation of these materials is not yet fully understood. As a representative example, InSe has attracted considerable attention due to its high charge mobility and Si-like band gap. However, conflicting observations such as oxidation by Se and In have been reported, including contrasting assessments of the oxidation susceptibility. In this study, we report in situ spectroscopy results detailing the origins of various oxidation pathways. We observed that at low defect densities the reduced reaction barrier of InSe due to Se vacancies leads to oxygen adsorption, while as defects increase, the lower electronegativity of In rises as a new pathway for oxidation. At low defect density, the bulk layer was more energetically favored for oxygen adsorption, allowing oxygen to diffuse to a depth sufficient to form pseudoheterojunctions and making the surface layer seemingly resistant to oxidation. Our results provide an answer to why the resulting diversity of optical responses is expected to increase as well as strategies to achieve gas stability.

Modeling and simulation of the structural, and optoelectronic properties of aluminum trihydride (β-[formula omitted]) for hydrogen storage

Hydrogen is a promising clean energy source, but its storage poses challenges. In this research, we conducted an in-depth study of the structural and optoelectronic properties of the β-AlH3 phase as a potential material for hydrogen storage. Using the density functional theory (DFT)-based Wien2k code, we optimized the structure of β-AlH3. Hydrogen storage properties show that β-AlH3 contains 10.1% hydrogen by weight, which is a significant amount. Electronic properties reveal that this material is a semiconductor with a wide indirect bandgap of 5.947 eV, obtained by the generalized gradient approximation with modified Becke-Johnson correction (GGA-mBJ). The optical response of β-AlH3 to photons with energies from 0 to 10 eV is also examined for a better understanding of this material. β-AlH3 exhibits a static dielectric permittivity value ε1(ω) of 2.1, indicative of its semiconducting nature. The optical conductivity σ1(ω) shows peaks at 7.25 eV and 8.5 eV, while the absorption coefficient α(ω) increases significantly above the band gap of 5.947 eV, with peaks at 7.2 eV and 9 eV. The refractive index n(ω) and extinction coefficient κ(ω) both display notable features at 7.2 eV and 9 eV, reflecting substantial electronic transitions and optical resonances.This research is crucial to understanding how this material can meet the technological demands of hydrogen storage. The results provide valuable insights into the potential of β-AlH₃ within the future energy landscape, highlighting both advances and challenges in this promising field.

A Porphyrin-Based MOF Thin Film with Oriented Nanosheet Arrays for Optimizing a Nonlinear Optical Response.

Developing two-dimensional (2D) hybrid nanosheet arrays integrating inorganic and organic components is highly significant for third-order nonlinear optical (NLO) applications. Herein, an oriented 2D porphyrin-based MOF (ZnTPyP(Co)) thin film composed of vertically stacked ultrathin nanosheets was fabricated via the liquid-phase epitaxial (LPE) layer-by-layer (LBL) method. The prepared ZnTPyP(Co) thin film exhibits an outstanding third-order NLO response with a high third-order nonlinear susceptibility of ∼2.63 × 10-7 esu, which is ascribed to the hybrid nanosheet array structure. Additionally, experimental Z-scan measurement and theoretical calculations also demonstrate that the substitution of Co metal ions in the porphyrinic core can increase the level of delocalization of the porphyrinic group and contribute to the material's enhanced NLO properties. These findings not only provide new film candidates for NLO application but also highlight the potential of 2D MOF nanosheets in advanced optical devices.

Patterned Lead-Free Double Perovskite/Polymer Fluorescent Piezoelectric Composite Films for Advanced Anti-Counterfeiting.

The limitations of single fluorescent anti-counterfeiting technologies necessitate the development of more sophisticated encryption methods to protect information and data. Traditional optical anti-counterfeiting encryption techniques, which rely on light sources with varying wavelengths to identify information, are now insufficient to meet contemporary security demands due to their restricted response to a narrow range of wavelengths. In this study, the fabrication of patterned, lead-free double perovskite (DP)/poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) fluorescent piezoelectric composite films (CFs) is reported. These CFs integrate the up-conversion and down-conversion photoluminescent properties of Cs2Na0.8Ag0.2BiCl6:Yb3+/Er3+ DP crystals with the piezoelectric properties of P(VDF-TrFE) film, facilitating multi-modal information protection. The fluorescent signals of different concealed information in CFs are observable under the excitation of 365nm UV light and 980nm infrared (IR) light. Additionally, external pressure applied at various locations on the CFs generates corresponding electrical signals, thereby providing triple-layer encryption for protected information. A multifunctional anti-counterfeiting device has been further developed by integrating patterned optical and electrical responses onto flexible CFs, achieving synergistic protection of information security in cross fields and bringing a significant advancement to the high-level anti-counterfeiting market.

Preparation and Growth Mechanism of Pyramid‐Shaped Cu2ZnSnS4 Monocrystal and the Simulation of Its Monograin Layer Solar Cells

AbstractThe Cu2ZnSnS4(CZTS) monocrystal as an important component of the optical absorption layer in monograin layer solar cells, has excellent crystallization characteristics and adjustable photogenerated carrier concentration. The shape of the CZTS monocrystal directly affects the utilization of incident light and the contact area during the preparation of the back electrode when they are densely packed to form a single‐layer absorption layer. Herein, a kesterite‐phase pyramid‐shaped CZTS monocrystal prepared by the molten salt method is reported, which can improve the efficiency of incident light utilization and increase the contact area during back electrode preparation. The X‐Ray diffraction, Raman spectroscopy, transmission electron microscopy, and scanning electron microscopy are used to characterize the crystallinity and crystal shape of pyramid‐shaped CZTS monocrystal. Besides, Finite‐Difference simulation calculation is employed to reveal the optical response and corresponding monograin layer solar cells performance of densely packed CZTS. The results show that the pyramid‐shaped structure exhibited excellent incident light trapping ability, and the simulated device achieves a cell efficiency with above 13.6% after parameter optimization. The work provides a method for preparing pyramid‐shaped CZTS monocrystal, and a new strategy to further improve the efficiency of CZTS‐based monograin layer solar cells.

Ultrafast Excitonic Transitions in Enantiopure and Racemic Squaraine Thin Films

ABSTRACTWhile chirality is a prevalent character of numerous biological and synthetic organic molecules, its selective absorption of circularly polarized light, known as circular dichroism (CD), is typically small due to intrinsically weak coupling between magnetic and electric dipoles. However, thin films of aggregated, enantiopure prolinol‐derived squaraine molecules (ProSQ‐C16) exhibit an unusually large excitonic CD signal, although the underlying mechanism is not yet known. In this study, we employ steady‐state and ultrafast transient absorption spectroscopy to investigate the nature and dynamics of excitons in aggregates of enantiopure and racemic ProSQ‐C16 thin films. Highly resembling transient responses of enantiopure thin films under excitations at different photon energies strongly indicate that a single type of aggregate dominates the linear optical response, that is, a strong red‐shifted (J‐like) and weak blue‐shifted (H‐like) absorption band. On the other hand, the transient properties of the racemic thin film deviate from this pattern and remain largely ambiguous. The short lifetime of excited states and coherent oscillations present in the dynamics of the transient absorption signal indicate that the early time dynamics are governed by a transition towards a dark intermediate state, which might arise from intermolecular charge transfer with potential contributions from the coupling of excitons to the vibrations. This non‐radiative relaxation pathway explains the unusually weak fluorescence of the predominately J‐like behaving aggregate. Our findings conclusively show that the chiral aggregate structure has a strong impact on the optical and dynamic response of the excitons and underline the significance of non‐Frenkel exciton states for the optical properties of anilino squaraine dyes.

Excitonic Effects on the Ultrafast Nonlinear Optical Response of MoS2 and Fluorinated Graphene/MoS2 Heterostructure Films for Photonic Applications.

In the present work, the ultrafast nonlinear optical (NLO) response of some molybdenum disulfide (MoS2), fluorinated graphene (FG), and FG/MoS2 heterostructure thin films was studied using the Z-scan and optical Kerr effect techniques employing femtosecond laser pulses at different excitation wavelengths (i.e., 400, 570, 610, 660, 800, and 1200 nm). The experiments have shown that the NLO response of the MoS2 and MoS2/FG films was significantly enhanced when the films were excited with 400, 610, and 660 nm laser pulses due to resonance effects with the close-lying excitons in these nanostructures. For a better evaluation of the resonant enhancement of the NLO response, measurements were also carried out at off-resonant wavelengths, i.e., at 570, 800, and 1200 nm. The presence of excitons in the MoS2 and MoS2/FG films resulted in strong saturable absorption and self-defocusing, with exceptionally large values of third-order susceptibilities χ(3) ranging from 10-12 to 10-13 esu. In addition, the NLO response of the MoS2/FG heterostructure was found to be stronger than that of the individual MoS2 and FG films, most probably attributed to interlayer carrier transfer. The determined NLO parameters of the studied nanostructures were found to be comparable to, and in some cases exceeded, those of other reported 2D materials known to exhibit a strong NLO response as well. These findings not only advance the fundamental understanding of the contributions of excitons on the NLO response/properties of transition metal dichalcogenide-based ultrathin films but also highlight the importance of excitons for tailoring their NLO response in view of various applications in advanced optoelectronics and photonic devices.

Atomic Layer Deposition for Stable InP-Based On-Chip Quantum Dot microLEDs: Hybrid Quantum Dot Pockets.

Recent advances in synthesis techniques yield InP-based QDs with optical properties comparable to those of benchmark Cd-based QDs, making InP-based QDs viable alternatives to toxic Cd-based QDs for applications such as quantum dot LEDs (QLEDs). However, QLEDs typically suffer from a loss of luminescence over time due to exposure of the QDs to ambient air. To avoid this, state-of-the-art hybrid barrier layers are explored consisting of alternating organic/inorganic layers. In this study, InP-based QD thin films and InP-based QDs embedded in Kraton polymers are encapsulated with a thin metal oxide barrier layer by atomic layer deposition (ALD). Specifically, Al2O3, TiO2, and ZnO thin films are deposited using trimethylaluminum (TMA), tetrakis(dimethylamino)titanium (TDMAT), and diethylzinc (DEZ), with H2O as the reactant. In situ photoluminescence (PL) is used to evaluate the optical response of the InP-based QDs during the ALD coating. The results show that ALD on pristine QD thin films causes degradation of luminescence, while this is not observed for polymer-embedded QDs. The long-term stability of the (ALD-coated) samples is investigated by accelerated degradation in a humidity chamber at a high temperature. Using a single Al2O3 ALD thin film as a capping layer for polymer-embedded QDs, greater stability of the QD-PL over a period of at least 300 h is found compared to pristine QD samples. A similar study is performed with InP-based QDs embedded in UV-patterned polymer (thiol-ene) structures, the so-called QD pockets, envisioned for use in on-chip quantum dot microLEDs. These QD pockets are purposefully designed for pick-and-place operations to reduce the complexity of the on-chip quantum dot microLED manufacturing process. The PL stability was significantly improved after incorporating Al2O3 ALD thin films, with these hybrid QD pockets showing no clear signs of degradation after 140 h. The combination of polymer embedding and ALD with the merits and scalability of the QD pocket structure is demonstrated to be an effective approach to improving the long-term QD stability and shows promise for the development of stable, InP-based on-chip quantum dot microLEDs.