Quantum Efficiency Research Articles

Metal-semiconductor-metal UVA photodetector based on TiO2 thin films synthesized via liquid phase deposition method

In this work, titanium dioxide (TiO2) thin film-based metal-semiconductor–metal (MSM) ultraviolet (UV) photodetectors (PDs) were fabricated on glass substrates via liquid phase deposition (LPD) technique at various deposition time in the range of 3–6 h. Varying deposition time significantly impacted the physical properties of the films. Increasing the deposition time revealed a mixture of clusters and hexagonal-like structures in film’s morphology. The energy band gap of the TiO2 films decreased from 3.30 to 3.09 eV upon increasing the deposition time. Photodetection characteristics were examined by exposing the MSM UV PD to 390 nm UV light with an intensity of 1.6 mW cm−2 and a bias voltage of 5 V. The fabricated PDs implied characteristics of I-V ohmic contact. The optimum photodetection characteristics were achieved for TiO2 film deposited at 6 h which exhibited 36.9 μA maximum photocurrent, 20080.3% sensitivity, 201.80 gain, 225 mA W−1 responsivity, 81.07% external quantum efficiency, 0.276 s response time, and 0.274 s recovery time. The photoelectric properties of the films were strongly affected by the increased grain size and improved crystallinity of the films due to the prolonged deposition time. The optimum film demonstrated its potential to be a promising candidate for UV PD applications.

Efficient and Stable Blue Perovskite Light‐Emitting Diodes Enabled by Effective Hydrolysis of Dichloride

AbstractDespite the substantial progress in sky‐blue (480−495 nm) perovskite light‐emitting diodes (PeLEDs), the pure‐blue PeLEDs (<480 nm) merely show moderate performances. As a straightforward and effective facile way to obtain pure‐blue emission, the bromide‐chloride mixed perovskites have received considerable attention. However, the tricky issue of halide migration in the mixed halide perovskites makes a tough challenge to achieve efficient PeLEDs with stable electroluminescence (EL) spectra. Herein, the in situ treatment of Cl‐rich benzene phosphorus oxydichloride (BPOD) is proposed to achieve high‐quality pure‐blue perovskites by simultaneously enlarging the perovskite bandgap, passivating the halide vacancy defects, and immobilizing the halide ions through the hydrolysis products of chloride ions and phenylphosphonic acid. As a result, highly‐performed pure‐blue PeLEDs with a maximum external quantum efficiency (EQE) of 9.3% at 477 nm, an impressive lifetime of 34.7 min at 104 cd m−2, and very stable EL spectra are achieved, which are superior to the conventional mixed halide PeLEDs based on lead‐chloride precursor, representing one of the best performances for mixed halide pure‐blue PeLEDs. Therefore, this work contributes a feasible and effective method for efficient and stable pure‐blue PeLEDs.

Static Organic p-n Junctions in Photoelectrodes for Solar Ammonia Production with 86% Internal Quantum Efficiency.

For photoelectrocatalytic cells, a limitation exists in finding appropriate photoelectrode configurations that couple efficient extraction of high-energy electrons from absorbed photons and selective catalysis. Here we report an organic p-n junction approach to fabricate molecular photoelectrodes for conversion of solar energy and nitrate into valuable ammonia product. Solar irradiation of the photoelectrode generates charge-separated states with electrons and holes spatially separated at the n-type and p-type components, as revealed by surface photovoltage mapping, at a quantum yield of 90%. The high-flux photogenerated electrons are rapidly transferred to the catalyst for solar ammonia production from nitrate reduction at an external quantum efficiency (EQE) and an internal quantum efficiency (IQE) of 57% and 86%, respectively. Time-resolved spectroscopic studies reveal that the large IQE originates from the combined high efficiencies for photoelectron generation, catalyst activation and dark catalysis. In a flow-cell setup coupled with a silicon solar cell, the photoelectrode without bias generates photocurrent of 57 mA cm-2 and ammonia at an EQE of 52%.

Static Organic p‐n Junctions in Photoelectrodes for Solar Ammonia Production with 86% Internal Quantum Efficiency

For photoelectrocatalytic cells, a limitation exists in finding appropriate photoelectrode configurations that couple efficient extraction of high‐energy electrons from absorbed photons and selective catalysis. Here we report an organic p‐n junction approach to fabricate molecular photoelectrodes for conversion of solar energy and nitrate into valuable ammonia product. Solar irradiation of the photoelectrode generates charge‐separated states with electrons and holes spatially separated at the n‐type and p‐type components, as revealed by surface photovoltage mapping, at a quantum yield of 90%. The high‐flux photogenerated electrons are rapidly transferred to the catalyst for solar ammonia production from nitrate reduction at an external quantum efficiency (EQE) and an internal quantum efficiency (IQE) of 57% and 86%, respectively. Time‐resolved spectroscopic studies reveal that the large IQE originates from the combined high efficiencies for photoelectron generation, catalyst activation and dark catalysis. In a flow‐cell setup coupled with a silicon solar cell, the photoelectrode without bias generates photocurrent of 57 mA cm‐2 and ammonia at an EQE of 52%.

Stepwise One-Shot Borylation Reactions for Intersecting DABNA Substructures Exhibiting Bright Yellow‒Green Electroluminescence with EQE Beyond 40% and Mild Roll-Off.

Boron/nitrogen (B/N)-doped polycyclic aromatic hydrocarbons (PAHs) with the multiple resonance (MR) effect are promising for organic light-emitting diodes (OLEDs) because of their narrowband emission and thermally activated delayed fluorescence (TADF) characteristics. Nevertheless, exploring the variety of such emitters is challenging because of the tricky and limited synthetic protocols. Herein, we designed a novel B/N-doped PAH, L-DABNA-1, whose backbone (L-DABNA) could not be achieved via conventional routes (e.g., one-pot borylation or one-shot borylation). We successfully synthesized it through stepwise one-shot borylations with precisely introducing decorations. The unique MR backbone with intersecting DABNA substructures sharing an aniline group, avoiding any para-N-π-B motif, allows L-DABNA-1 to maintain narrowband TADF emission while significantly redshifting to the yellow-green region with a reverse intersystem crossing rate (kRISC) of 1.28 × 105 s-1. An L-DABNA-1-based OLED device achieved a maximum external quantum efficiency (EQE) of over 40% and maintained a high EQE of 36.3% at 1000 cd m-2, with a current efficiency reaching ~170 cd A-1. This work not only demonstrated the great potential of stepwise borylations in synthesizing B/N-doped PAH backbones, expanding their chemical space, but also provided a promising pathway for exploring MR-TADF emitters at longer wavelengths.

Stepwise One‐Shot Borylation Reactions for Intersecting DABNA Substructures Exhibiting Bright Yellow‒Green Electroluminescence with EQE Beyond 40% and Mild Roll‐Off

Boron/nitrogen (B/N)‐doped polycyclic aromatic hydrocarbons (PAHs) with the multiple resonance (MR) effect are promising for organic light‐emitting diodes (OLEDs) because of their narrowband emission and thermally activated delayed fluorescence (TADF) characteristics. Nevertheless, exploring the variety of such emitters is challenging because of the tricky and limited synthetic protocols. Herein, we designed a novel B/N‐doped PAH, L‐DABNA‐1, whose backbone (L‐DABNA) could not be achieved via conventional routes (e.g., one‐pot borylation or one‐shot borylation). We successfully synthesized it through stepwise one‐shot borylations with precisely introducing decorations. The unique MR backbone with intersecting DABNA substructures sharing an aniline group, avoiding any para‐N‐π‐B motif, allows L‐DABNA‐1 to maintain narrowband TADF emission while significantly redshifting to the yellow–green region with a reverse intersystem crossing rate (kRISC) of 1.28 × 105 s−1. An L‐DABNA‐1‐based OLED device achieved a maximum external quantum efficiency (EQE) of over 40% and maintained a high EQE of 36.3% at 1000 cd m−2, with a current efficiency reaching ~170 cd A−1. This work not only demonstrated the great potential of stepwise borylations in synthesizing B/N‐doped PAH backbones, expanding their chemical space, but also provided a promising pathway for exploring MR‐TADF emitters at longer wavelengths.

Absorption and quantum efficiency of GeSn nanopillar arrays for infrared detectors

Abstract This research investigates the optical absorption and quantum efficiency of germanium-tin (GeSn) materials with a tin(Sn) content of 4.5%, and their potential applications in infrared optoelectronic systems. It has two forms which are crystalline(c-GeSn) and amorphous(a-GeSn) states. The finite-difference time-domain (FDTD) method was used to simulate the absorption of c-GeSn and a-GeSn. By optimising the period, radius and height of the nanopillars, the optimal parameters were determined, and it was found that the c-GeSn nanopillars in that case had a very stable and excellent absorption in the near-infrared (NIR) band. Calculated by MATLAB that the cylindrical nanopillars could reach a maximum quantum efficiency of 3.67% at 1350 nm. It is anticipated that this study will contribute to the further understanding of GeSn and provide a theoretical basis for designing high-performance infrared photodetectors.

Effect of Drought and Rehydration on Physiological Characteristics of Agriophyllum squarrosum (L.) Moq. in Different Habitats

Agriophyllum squarrosum (L.) Moq. is a highly prevalent xerophytic species found throughout northern China. It is suitable for cultivation in semi-arid sandy environments and may establish roots in arid desert locations. This species plays a pioneering and exploratory role in the colonization of desert plants. In this study, we selected A. squarrosum from the Urat desert steppe (UD) and Horqin sandy land (HS) to explore their adaptation mechanisms to drought and rehydration environments by using the pot weighing control method to simulate an arid environment. The findings showed that the control (watering to 60–65% of field capacity) exceeded its required amount and the leaves turned yellow. The chlorophyll content was lower than those under moderate and severe drought, and rehydration caused a decrease. However, the contents of malondialdehyde, soluble sugar, and proline in the drought treatment were higher than those in the control. Under moderate and severe drought, the chlorophyll content and the quantum efficiency of photosystem II (Fv/Fm) of A. squarrosum from UD were higher than those from HS. During drought and rehydration processes, the proline content was relatively lower, while the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) and the content of soluble sugar and soluble protein were higher. However, antioxidant enzymes and osmoregulators from UD were higher than those from HS. The results suggest that the stronger ability of A. squarrosum to endure drought environments in UD is due to the high level of antioxidant enzymes and osmoregulators, which are conducive to relieving cell membrane damage when subjected to drought and rehydration.

Temperature dependent self-assembly of lanthanide coordination polymers based on a benzimidazolium dicarboxylate linker: synthesis, structure and luminescence properties

Five new coordination polymers, namely [Ln(L)(NO3)2]n (Ln = La (1), Pr (2) and Sm (3)), [Eu(L)(NO3)2·1.5H2O]n (4) and [Tb(L)(OAc)2(H2O)·3H2O]n (5) (HOAc = CH3COOH), were synthesised by reaction of lanthanide nitrates with 1,3-bis(4-carboxybenzyl)benzimidazolium chloride (H2L+Cl−) under solvothermal conditions. All the coordination polymers were characterised by powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, elemental analysis and single crystal X-ray diffraction. Complexes 1–5 exhibit two different 2-D structures due to the variation in reaction temperature. Complexes 1–4 are isostructural and crystallised in the monoclinic system, C2/c space group, showing a two-dimensional layer with Ln chains linked by L− ligands. Complex 5 crystallised in the P21/n space group, featuring a 2-D layer different from 1–4 with Tb dimers linked by L− ligands through carboxylates. Further, the luminescence properties of complexes 3–5 were investigated. In addition, the fluorescence lifetime and quantum efficiency of complex 4 were measured.

Enhancing Performance in Top‐Illuminated Shortwave Infrared Organic Photodetectors via Microcavity Resonance

AbstractShortwave infrared (SWIR) image sensors have unique functions in many optical applications, leading to widespread attention in developing next‐generation materials and photodetector technologies. Organic photodetectors (OPDs) are highly promising due to their flexibility in molecular design and processability. However, integrating OPDs with silicon readout integrated circuits (ROICs) poses numerous challenges, often resulting in underestimated device performance and limiting technological progress. To address the requirements of integrating top‐illuminated OPD with ROICs and to enhance the external quantum efficiency (EQE), optical microcavities are introduced into the OPDs. The EQE in the SWIR region can be effectively enhanced by properly adjusting the thicknesses of the photoactive layer (PAL) and interlayers. Simulations of the optical field distribution further support the active functions of the microcavity structure. The spatial variation of the microcavities allows the spectral response to shift from 1000 to 1400 nm, and the optimized device achieves an EQE of 25.8% at 1260 nm. Finally, the OPDs are integrated with a silicon‐based test kit, and the results reveal comparable sensing performance, demonstrating the high potential of microcavity resonance for device integration. This design effectively improves the integration of OPDs with traditional ROICs and advances SWIR‐based organic image sensor technology further toward commercialization.

Enhancing Spin-Orbit Coupling in an Indolocarbazole Multiresonance Emitter by a Sulfur-Containing Peripheral Substituent for a Fast Reverse Intersystem Crossing.

A fast reverse intersystem crossing (RISC) remains an ongoing pursuit for multiresonance (MR) emitters but faces formidable challenges, particularly for indolocarbazole (ICz) derived ones. Here, heavy-atom effect is introduced first to construct ICz-MR emitter using a sulfur-containing substitute, simultaneously enhancing both spin-orbit and spin-vibronic coupling to afford a fast RISC with a rate of 1.2×105s-1, nearly one order of magnitude higher than previous maximum values. The emitter also exhibits an extremely narrow deep-blue emission peaking at 456nm with full-width at half-maxima of merely 12nm and a photoluminescence quantum yield of 92%. Benefiting from its efficient triplet upconversion capability, this emitter achieves not only a high maximum external quantum efficiency (EQE) of 31.1% in organic light-emitting diodes but also greatly alleviates efficiency roll-off, affording record-high EQEs of 29.9% at 1000cdm-2 and 18.7% at 5000cdm-2 among devices with ICz-MR emitters.

High Efficiency Non‐Doped Organic Light Emitting Diodes Based on Pure Organic Room Temperature Phosphorescence by High‐Lying Singlet Exciton Fission

AbstractHeavy‐metal‐free pure organic room temperature phosphorescence (ORTP) holds great potential in the field of organic optoelectronic devices owing to low economic cost, simple preparation techniques, and high exciton utilization. However, it is still filled with challenges in realizing high efficiency organic light‐emitting diodes (OLEDs) and exploring the internal physical mechanism based on these ORTP molecules. Here, a high‐performance OLED induced by an unexpected interfacial spin‐mixing process between the ORTP molecule and interlayers is demonstrated, and the high efficiency electroluminescence (EL) mechanism is studied through magneto–electroluminescence (MEL) and magneto–photoluminescence (MPL) measurements. The steady‐state and transient PL properties imply that the interfacial effect is related to a high‐lying singlet fission (HLSF) process in the ORTP molecule itself. Further, the HLSF process and the corresponding energy level position are confirmed by the incident wavelength‐ and temperature‐dependent PL spectra and the magnetic‐field‐dependent transient PL. Finally, by optimizing the interfacial material adjacent to the emissive layer to utilize this interfacial spin mixing effect, a high‐efficiency non‐doped ORTP‐OLED with external quantum efficiency of 16% and CIE coordinates of (0.27, 0.49) is developed. The proposed mechanism during the EL process will give insight to produce more efficient OLEDs based on ORTP materials in the future.

High-Performance CsPbI3 Quantum Dot Photodetector with a Vertical Structure Based on the Frenkel-Poole Emission Effect.

The selection of photoactive materials and the design of device structures are critical to the photoelectronic performance of photodetectors. This study reports on a vertically structured photodetector device with rapid, stable, and efficient photoelectric performance across the UV-visible broadband range based on the Si++/SiO2/Au/single-layer graphene/CsPbI3 quantum dots (QDs) configuration. In this specific device structure, a relatively high conductivity Si++/SiO2 wafer was used as the substrate, a CsPbI3 QD film with high light absorption was used as the photoactive layer, and a monolayer graphene with high conductivity was inserted between the substrate and the CsPbI3 QD film to form a heterojunction with the QD film. Based on the Frenkel-Poole emission effect arising from the high trap state density within the SiO2 layer, the device exhibited excellent photoelectric performances. Especially at a wavelength of 365 nm, a photocurrent responsivity of 2319 A/W, a specific detectivity of 1.15 × 1014 Jones, an external quantum efficiency of 7883%, and an on/off time of 39/36 ms at a Si++ terminal voltage of -80 V and an optical power density of 84.03 nW/cm2 can be achieved.

Design and numerical investigation of Cs2SnI6 vacancy-ordered double perovskite solar cell

Perovskite solar cells (PSCs) represent an emerging technology in solar photovoltaics due to their outstanding optical and electrical characteristics. The urgency of lead-free solar materials has increased due to the environmental concerns. In light of these considerations, Cs2SnI6, a high-performance tin-based double perovskite, holds the potential to be a key absorber material in promoting the cell efficiency. In this paper, a device design of lead-free Cs2SnI6-based PSC is proposed based on an n-i-p planar structure. Through a comprehensive analysis by simulation using SCAPS-1D, the impacts of electron transport layer materials (SnO2, TiO2, CdS, GO, MZO) and hole transport layer materials (MoO3, Cu2O, CuI, Spiro-OMeTAD) with varying thicknesses as well as the donor density, acceptor density and the absorber thickness have been examined. Additionally, an examination is conducted on the performance metrics of PSCs, encompassing Voc, Jsc, FF, and PCE, while taking into consideration the influences of temperature, Rseries, and Rshunt. The results show that the optimized FTO/SnO2/Cs2SnI6/MoO3/Au device presents the highest PCE of 22.60 % at 300 K temperature, together with a visible quantum efficiency of 99.49 %. The appropriate thicknesses of the ETL, HTL, and absorber layer for achieving the optimal performances are 50 nm, 200 nm, and 450 nm, respectively. Also, the donor density and acceptor density for the best efficiency are both at 1018 cm−3. The values of Rseries, and Rshunt are 2 Ω cm2 and 6000 Ω cm2, respectively. This investigation demonstrates that the proposed vacancy-ordered double perovskite Cs2SnI6 solar cell is promising for photovoltaic devices due to the highlighted characteristics and optical parameters.

Terpyridine-Based Metal-Organic Cage with Enhanced Emission via Coordination-Induced Rigidity.

Realizing the regulation of photophysical properties by precisely controlling the molecular composition and configuration, thereby obtaining high-performance optical materials, remains of great significance. Due to the directionality and reversibility of the coordination bond, coordination-driven self-assembly endows the molecule with customized thermodynamically stable structures and desired properties. In this paper, a luminous metal-organic cage [Zn12L6] (S) was elaborately designed and quantitatively synthesized by self-assembly of tetrapodal TQPP chromophore-containing terpyridine ligand L with Zn2+. Complex S possessed a rigid cage-like structure, which endows a higher fluorescence quantum efficiency both in solution (∼88%) and neat solid (16%) than the corresponding ligand L. Further, using complex S as the photoactive component, two light-emitting diodes (LEDs) were successfully fabricated and the emission of pure white light (CIE coordinates: 0.3341, 0.3300) was achieved. These results afford a method to obtain enhanced luminescence performance via the formation of rigid coordination-driven supramolecular architectures.

Optimizing CuInSe2 Solar Cells with Kesterite-Based Upper Absorber and Back Surface Field Layers for Enhanced Efficiency: A Numerical Study

Abstract This study explores the performance enhancement of an innovative multi-layer solar cell structure using the SCAPS-1D (Solar Cell Capacitance Simulator in One Dimension) software. We aim to improve the efficiency of a solar cell structure comprising ZnO/ZnSe/CZTSe/CuInSe2/CZTSSe/Mo by incorporating CZTSe as the upper absorber layer, CuInSe2 as the main absorber layer, and CZTSSe as a back surface field (BSF) layer. Initially, we compare the performance of three different configurations by analyzing their J-V characteristics. For the best performing structure, we further examine the external quantum efficiency (EQE) spectrum. We then evaluate various window (ZnO, ZnMgO, SnO2, Zn2SnO4) and buffer (ZnSe, ZrS2, SnS2, In2S3) materials, identifying ZnO and ZrS2 as the most effective for achieving high current density and efficiency. Through detailed simulations, we determine the optimal thicknesses for CZTSSe (0.2 µm), CZTSe (0.4 µm), and CuInSe2 (3.2 µm). Additionally, by optimizing the acceptor density to 1020 cm−3, we significantly enhance the performance of both CZTSe and CZTSSe layers. Temperature management is shown to be crucial, with the highest efficiency observed at 300 K. As a result of these optimizations, the solar cell structure achieves a remarkable efficiency of 35.38%. Furthermore, we compare our results with existing literature to highlight the advancements made in this study. These findings underscore the importance of material selection and structural optimization in developing high-efficiency solar cells and provide a framework for future advancements in photovoltaic technology.

Bright Structural-Phase-Pure CsPbI3 Core-PbSO4 Shell Nanoplatelets With Ultra-Narrow Emission Bandwidth of 77 meV at 630 nm.

Achieving a narrow emission bandwidth islong pursued for display applications. Among all primary colors, obtaining pure red emission with high visual perception is the most challenging. In this work, CsPbI3 halide perovskite nanoplatelets (NPLs) with rigorously controlled 2D [PbI6]4- octahedron layer number (n) are demonstrated. A perovskite core-PbSO4 shell structure is designed to prevent aggregation and fusion between NPLs, enabling consistent thickness and quantum confinement strength for each NPL. Consequently, exact n = 4 CsPbI3NPLs are demonstrated, exhibiting emission peaks around 630nm, with very narrow spectral bandwidths of <24nm and high absolute photoluminescence quantum yields up to 85%. The emission of n = 4 NPLs falls exactly within the pure-red region, closely aligning with the International Telecommunication Union Recommendation BT.2020 standard. Measurements suggest predominant stability and color homogeneity compared to traditional red-emitting CsPbIxBr3- x nanocrystals. Finally, proof-of-concept pure-red emissive light-emitting diodes (LEDs) are demonstrated by integrating n = 4 CsPbI3 NPLs films with a blue LED chip, showing an excellent external quantum efficiency of 18.3% and high brightness exceeding 3 × 106 nits. Stringent requirements for future display technologies, are satisfied based on the high color purity, stability, and brightness of CsPbI3 NPLs.

Multi-resonance thermally activated delayed fluorescence polymers for high-efficiency and narrowband solution-processed green OLEDs.

A series of green multi-resonance thermally activated delayed fluorescence polymeric emitters featuring conjugation-interrupted main chains were facilely prepared via metal-free superacid-catalyzed Friedel-Crafts polyhydroxyalkylation. These emitters exhibited photoluminescence quantum yields of up to 76% and small full-widths at half maximum of 35-38 nm in toluene. The corresponding solution-processed OLEDs achieved an excellent maximum external quantum efficiency of 19.4%, with CIE coordinates of (0.20, 0.62).

Rational Molecular Design of Phenanthroimidazole-Based Fluorescent Materials toward High-Efficiency Deep-Blue OLEDs by Molecular Isomer Engineering.

Organic light-emitting diodes (OLEDs) have been extensively investigated in full-color displays and energy-saving lighting owing to their unique advantages. However, deep-blue OLEDs based on nondoped emitting layers with a satisfactory external quantum efficiency (EQE) are still rare for applications. In this work, six hot exciton materials, PPIM-12F, PPIM-22F, PPIM-13F, PPIM-23F, PPIM-1CN, and PPIM-2CN, are designed and synthesized via an isomer engineering design strategy and their photophysical properties and OLED performance are systematically investigated. These emitters all possess wide band gaps (3.53-3.69 eV), hybrid local and charge transfer (HLCT) characteristics, and good thermal stabilities. The C2 series compounds, PPIM-22F, PPIM-23F, and PPIM-2CN, all show redder emission peaks than the N1 series counterparts of PPIM-12F, PPIM-13F, and PPIM-1CN. In addition, the LUMO energy levels decrease consecutively in the sequence of PPIM-22F < PPIM-23F < PPIM-2CN and are all lower than their respective N1 series position isomers of PPIM-12F, PPIM-13F, and PPIM-1CN. The CV measurements indicate that such a design strategy renders the fine-tuning of LUMO energy levels, and the incorporation of electron acceptors at the extended C2 position of the PI unit is a better choice to improve the electron injection ability. Theoretical simulations indicate that they may harvest the triplet exciton through an upper-level reverse intersystem crossing process, which decreases the gathering of triplet excitons and allows the OLEDs to be fabricated by nondoping technology. Among them, PPIM-22F with a difluorobenzene substituent at the C2 position manifests the best performance in OLEDs, which exhibits the maximum EQE of 7.87% and Commission Internationale de ĺEclairage (CIE) coordinates of (0.16, 0.10). This work demonstrates an effective strategy for considerable improvement in device performance by a subtle change in the molecular structure through isomer engineering.

Mitigating thermal burden and enhancing minor phase emission energy transfer in perovskite by introducing dopamine-mediated silver nanoparticles

Perovskite-based light-emitting diodes (PeLEDs) suffer from low wavelength and intensity instability during excited emission. This study incorporates dopamine-mediated silver nanoparticles (DA@AgNPs) into perovskite to enhance the performance of blue-light PeLEDs. Characterization studies highlight the crucial role of dopamine’s hydroxyl group in controlling the size and distribution of AgNPs. Due to the presence of amine group, dopamine acts as a “bridging linker,” facilitating precise integration of AgNPs with perovskite. DA@AgNPs–perovskite comprises a uniform cubic phase, indicating improved crystal quality and fewer defects than in pristine perovskite. DA@AgNPs prevent pinhole-defect-induced heat accumulation, reducing nonradiative energy and Joule heat. Additionally, DA@AgNPs enhance thermal conductivity and thus cooling efficiency. The energy transfer between minor and primary phase emissions is found to be highly efficient and to enhance primary phase emission through the surface plasmon resonance effect of DA@AgNPs. Finally, DA@AgNPs–perovskite is successfully employed in a high-performance blue-light PeLED (wavelength = 476 nm); the device’s external quantum efficiency is 11.2 %, luminance is 380.2 cd/m2, and emission stability is favorable (firmly maintained at 476–478 nm after strong excitation under 4.25 V for 1 h). This work provides insights into one means of improving blue-light PeLEDs, opening avenues for advancements in optoelectronics.