Low Defect Research Articles

A fuzzy classification method based on rules learning for shaded and unshaded hotspot faults on photovoltaic modules

Hotspots (HS) reduce the output power (P) of photovoltaic modules (PVMs) and sometimes lead to fires. However, it is difficult to effectively classify and detect HS faults. In this paper, we focus on the classification and detection of Shaded HS and Unshaded HS. HS faults not only occur due to non-uniform illumination and parameter mismatch but due to internal defects as well, such as; low resistance defects of a cell. The Shaded HS can be repaired sometimes by water washing, such as PVMs in the desert, while the Unshaded HS can only be repaired by replacing them. Therefore, to classify and detect such HS faults, we propose a fuzzy classification method based on data-driven rules learning. Firstly, the characteristic performances of Shaded and Unshaded HS PVMs are compared with the performances of normal PVMs. Secondly, the percentage reduction algorithm is presented for extracting three fault indicators to identify such HS faults. Then, a classification method is proposed using a technique called the Mamdani-type Fuzzy logic system, in which the rules are obtained by a process called the “Data-Driven Rule Generation Method”. Finally, a low-resistance HS model is built using Matlab Simulink. The simulation and experiment results show that the proposed method has more classification accuracy for Shaded and Unshaded HS faults.

Thermally Evaporated Blue Quasi-Two-Dimensional Perovskite Light-Emitting Diodes via Low-Dimensional Phase Distribution Arrangement.

Perovskite light-emitting diodes (PeLEDs) have shown great potential in the display domain due to their wide color gamut, narrow emission, and low cost. In current PeLEDs manufacturing methods, thermal evaporation shows great competitiveness with its advantages of easy patterning, production line compatibility, and solvent-free processability. However, the development of thermally evaporated blue PeLEDs is limited by their low radiative recombination rate and high defect density. Herein, we report high-performance thermally evaporated blue PeLEDs by in situ introduction of ammonium cations. We confirm that phenethylammonium (PEA+) has lower adsorption energy, which significantly reduces the low-n phases in a quasi-2D perovskite film. The energy transfer rate is also promoted by the PEA+ addition. As a result, we fabricate blue PeLEDs with an external quantum efficiency of 1.56% by thermal evaporation. The strategy of arranging phase distribution could benefit the industrialization of full-color PeLEDs.

Surgical reconstruction of medial eyelid defects using margin transposition, tarsal graft, and periosteal strip

ABSTRACT Purpose Surgical reconstruction of medially located lower eyelid defects can be challenging. The Hughes procedure, considered the standard for reconstruction in such cases, often falls short in terms of cosmetic outcomes. An alternative approach that combines medial transposition with a tarsal graft and periosteal strip has shown promise. Here, we aim to demonstrate the cosmetic advantages of medial transposition of a preserved temporal lower eyelid over other techniques. Method We conducted a retrospective study involving seven well-documented patients who underwent the procedure described below. The study was approved by the University’s Ethics Committee. Results All patients were followed up for one year. Lower eyelid defects spanned 50–80% of their total length, situated in the central third of the eyelid or the central to medial portion. Postoperative complications were minimal, with all patients exhibiting good cosmetic, functional, and anatomical outcomes at follow-up. Conclusion The absence of eyelashes is well tolerated if it is lateral, but when the defect is medial, medial transposition could be a good alternative to the familiar Hughes surgical intervention.

Regulating Surface Defects to Achieve More Positive Light Soaking Effect in Perovskite Solar Cells.

The dynamic defect tolerance under light soaking is a crucial aspect of halide perovskites. However, the underlying physics of light soaking remains elusive and is subject to debate, exhibiting both positive and negative effects. In this investigation, we demonstrated that surface defects in perovskite films significantly impact the performance and stability of perovskite solar cells, closely correlated with light soaking behaviors. Removing the top surface layer through adhesive tape, the surface defect density noticeably decreases, leading to enhanced photoluminescence (PL) efficiency, prolonged carrier lifetime, and higher conductivity. Consequently, the power conversion efficiency (PCE) of solar cells improves from 17.70% to 20.5%. Furthermore, we confirmed a positive correlation between surface defects and the light soaking effect. Perovskite films with low surface defects surprisingly exhibit a 3-fold increase in PL intensity and an 85% increase in carrier lifetime under 500 s of continuous illumination at an intensity of 100 mW/cm2. Beyond the conventional strategy of suppressing defect trapping, we propose increasing the capability of dynamic defect tolerance as an effective strategy to enhance the optoelectronic properties and performance of perovskite solar cells.

Modulating Lattice Oxygen Activity of Iron-Based Triple-Conducting Nanoheterostructure Air Electrode via Sc-Substitution Strategy for Protonic Ceramic Cells.

Iron-based perovskite air electrodes for protonic ceramic cells (PCCs) offer broad application prospects owing to their reasonable thermomechanical compatibility and steam tolerance. However, their insufficient electrocatalytic activity has considerably limited further development. Herein, oxygen-vacancy-rich BaFe0.6Ce0.2Sc0.2O3-δ (BFCS) perovskite is rationally designed by a facile Sc-substitution strategy for BaFe0.6Ce0.4O3-δ (BFC) as efficient and stable air electrode for PCCs. The BFCS electrode with an optimized Fe 3d-eg orbital occupancy and more oxygen vacancies exhibits a polarization resistance of ≈ 0.175Ωcm2 at 600°C, ≈ 1/3 of the BFC electrode (≈0.64Ωcm2). Simultaneously, BFCS shows favorable proton uptake with a low proton defect formation enthalpy (- 81kJmol-1). By combining soft X-ray absorption spectroscopy and electrical conductivity relaxation studies, it is revealed that the enhancement of Fe4+-O2- interactions in BFCS promotes the activation and mobility of lattice oxygen, triggering the activity of BFCS in both oxygen reduction and evolution reactions (ORR/OER). The single cell achieves encouraging output performance in both fuel cell (1.55 Wcm-2) and electrolysis cell (-2.96Acm-2 at 1.3V) modes at 700°C. These results highlight the importance of activating lattice oxygen in air electrodes of PCCs.

Sensory and pain outcomes of neurotized skin-grafted free gracilis muscle flaps for lower extremity reconstruction

BackgroundSkin-grafted free gracilis muscle flaps are commonly used for lower extremity reconstruction. However, the loss of sensory function may lead to increased patient morbidity. This study prospectively analyzed the sensory and neuropathic pain outcomes of neurotized skin-grafted free gracilis muscle flaps used for the reconstruction of lower extremity defects. MethodsPatients undergoing lower extremity reconstructions between 2020 and 2022 with neurotized skin-grafted free gracilis muscle flaps were prospectively enrolled. Sensation was assessed at 3, 6 and 12 months postoperatively using monofilaments, two-point discrimination, a vibration device, and cold and warm metal rods. Sensations were tested in the center and periphery of the flaps, as well as in the surrounding skin. The contralateral side served as the control. Patients completed the McGill pain questionnaire to evaluate patient-reported neuropathic pain. ResultsTen patients were included. At 12 months postoperatively, monofilament values improved by 44.5% compared to that of the control site, two-point discrimination, cold detection, warmth detection, and vibration detection improved by 36.2%, 48%, 50%, and 88.2%, respectively, at the reconstructed site compared to those at the control site. All sensory tests were significantly better than 3 and 6 months values (p < 0.05), but remained significantly poorer than the control site (p < 0.05). Sensation in the central flap areas were similar to peripheral flap areas throughout the follow-up period (p > 0.05). The surrounding skin reached values similar to the control site at 12 months (p > 0.05). Moreover, 50% of patients reported neuropathic pain at 3 months postoperatively, 40% at 6 months, and 0% at 12 months (p < 0.05). ConclusionMechanical detection, vibration detection, temperature detection, and two-point discrimination significantly improved over time but without reaching normal sensory function at 12 months postoperatively. Neuropathic pain resolved at 12 months.

Enhanced Amplified Spontaneous Emission from Perovskite Films by a Multifunctional 4′‐Aminoacetophenone Hydrochloride Additive Assistant Engineering

AbstractMetal halide perovskites are considered as a prospective candidate as optical gain media for stimulated emission, and the advancement of amplified spontaneous emission (ASE) of perovskite materials is gradually becoming the key to realize the commercialization of perovskite lasers. Nonetheless, the ASE of solution‐processed polycrystalline perovskite films still experiences a high threshold and poor optical stability due to their high defect density and poor crystalline quality. In this scenario, a noticeably ameliorated ASE performance with decreased threshold and greater photo‐stability is demonstrated in solution‐processed (FAPbI3)0.85(MAPbBr3)0.15 polycrystalline perovskite films by introducing a neoteric 4′‐Aminoacetophenone hydrochloride (APCl) additive with cost‐effective fabrication. The ASE threshold of the APCl‐embedded perovskite films is prominently curtailed from 12.8 to 5.3 µJ cm−2, with an augmented optical gain, ASE output intensity, and optical durability. The ameliorated ASE performance can be credited to multifunctional effects of the APCl additive in the perovskite films, presenting a low defect density, an unambiguously elevated photoluminescence, a prolonged decay lifetime and thus enabling the easily achieved population inversion caused by the attenuated nonradiative carrier recombination in the optical gain media. These findings provide a significant foundation and pave the way for realizing the electrically excited lasing based on the perovskite materials.

Medium-range order structure analysis of metallic glasses based on reverse Monte Carlo modeling

The elucidation of amorphous alloy characteristics presents a formidable challenge due to the absence of crystalline arrangements and enigmatic imperfections. This study aimed to tackle this challenge through a comprehensive investigation utilizing synchrotron X-ray diffraction (XRD), extended X-ray absorption fine structure spectroscopy (EXAFS), ab initio molecular dynamics (AIMD) simulations, and reverse Monte Carlo (RMC) modeling. The primary objective was to delve into the medium range order (MRO) structure of metallic glasses (MGs) containing CuXZr100-X, wherein X represents values of 50, 56, 60, and 64. The results obtained from this research demonstrate that an increase in the Cu atom concentration within Cu-Zr MGs leads to the formation of complete icosahedral clusters and high-coordination polyhedral connections, thereby bolstering the stability and heterogeneity of local structures. Examination of the stiff full icosahedral bones shows that defects exist in the network connections on the MRO, resulting in a lack of connectivity in the positive icosahedron. Conversely, the density of defects decreases with an increase in Cu content. The observation suggests that the observed low MRO defects in Cu64Zr36 MGs may be accountable for their excellent glass-forming ability and kinetic stability.

Accelerating defect predictions in semiconductors using graph neural networks

First-principles computations reliably predict the energetics of point defects in semiconductors but are constrained by the expense of using large supercells and advanced levels of theory. Machine learning models trained on computational data, especially ones that sufficiently encode defect coordination environments, can be used to accelerate defect predictions. Here, we develop a framework for the prediction and screening of native defects and functional impurities in a chemical space of group IV, III–V, and II–VI zinc blende semiconductors, powered by crystal Graph-based Neural Networks (GNNs) trained on high-throughput density functional theory (DFT) data. Using an innovative approach of sampling partially optimized defect configurations from DFT calculations, we generate one of the largest computational defect datasets to date, containing many types of vacancies, self-interstitials, anti-site substitutions, impurity interstitials and substitutions, as well as some defect complexes. We applied three types of established GNN techniques, namely crystal graph convolutional neural network, materials graph network, and Atomistic Line Graph Neural Network (ALIGNN), to rigorously train models for predicting defect formation energy (DFE) in multiple charge states and chemical potential conditions. We find that ALIGNN yields the best DFE predictions with root mean square errors around 0.3 eV, which represents a prediction accuracy of 98% given the range of values within the dataset, improving significantly on the state-of-the-art. We further show that GNN-based defective structure optimization can take us close to DFT-optimized geometries at a fraction of the cost of full DFT. The current models are based on the semi-local generalized gradient approximation-Perdew–Burke–Ernzerhof (PBE) functional but are highly promising because of the correlation of computed energetics and defect levels with higher levels of theory and experimental data, the accuracy and necessity of discovering novel metastable and low energy defect structures at the PBE level of theory before advanced methods could be applied, and the ability to train multi-fidelity models in the future with new data from non-local functionals. The DFT-GNN models enable prediction and screening across thousands of hypothetical defects based on both unoptimized and partially optimized defective structures, helping identify electronically active defects in technologically important semiconductors.

Pedicled Peroneus Brevis Muscle Flaps as an Alternative to Fasciocutaneous Rotational Flaps for Lower-Extremity Soft Tissue Defects.

To report our experience using a peroneus brevis flap (PBF) for soft tissue defects of the distal third of the tibia, ankle, and hindfoot in resource-challenged environments. Retrospective review. Rural outpatient surgical facility in Honduras. Patients who sustained tibia, ankle, or hindfoot fractures or traumatic degloving, with critical-sized soft tissue defects treated with either a proximally based or distally based pedicled PBF to achieve coverage of the middle and distal third of the leg, ankle, and/or hindfoot. Flap healing, complications, and reoperations. Twenty-three patients, 4 with proximally based and 19 with distally based PBF flaps were included. The mean patient age was 37.3 (SD = 18.3; range 18-75 years). Duration of follow-up averaged 14.7 months (SD = 11.4; range 4-46). The PBF successfully covered the defect without the need for additional unplanned surgical flap coverage in all but 2 patients. Thirty percent of the PBFs received a split thickness skin graft, while the remainder granulated successfully without skin graft. Four flaps were partially debrided without additional flap mobilization, while 1 flap was lost completely. Ten patients had successful re-elevation of their flaps for secondary procedures such as implant removal, spacer exchange, deep debridements, and bone grafting. All donor site incisions healed without complication. The pedicled PBF allows coverage of distal leg, ankle, and hindfoot wounds using muscle in patients who may otherwise require free tissue flaps or transfer to another institution for coverage. PBFs can be learned and implemented without the use of microvascular techniques. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

C2DEM-YOLO: improved YOLOv8 for defect detection of photovoltaic cell modules in electroluminescence image

ABSTRACT Photovoltaic (PV) cell modules are the core components of PV power generation systems, and defects in these modules can significantly affect photovoltaic conversion efficiency and lifespan. Electroluminescence (EL) testing is a method used to detect defects during the production process of these modules. To address the issue of low defect detection accuracy caused by the complex background and large-scale variations of EL images, we propose an object detection network named C2DEM-YOLO to improve the accuracy of defect detection. Firstly, a deep-shallow feature extraction module called C2Dense is designed to replace the C2f module in the YOLOv8’s backbone. Secondly, a cross-space multi-scale attention(EMA) is introduced after C2Dense to apply pixel-level attention to the extracted features, which suppresses background information while enhancing useful features for defect detection. Finally, by replacing CIoU with Inner-CIoU, we introduce auxiliary regression boxes to improve the accuracy of detection and the generalisation ability of the model. Experimental results show that C2DEM-YOLO achieves an average precision of 92.31% on the PVEL-AD dataset, which has 2.41%, 1.93%, and 1.56% improvement compared to YOLOv5s, YOLOv8n, YOLOv8s, respectively. Moreover, on our self-built dataset, the mAP@0.5 and mAP@0.5:0.95 of C2DEM-YOLO are improved by 1.42% and 1.46% compared to YOLOv8n, reaching 84.07%.

Niobium doping of CVD-WS2 monolayers using solid precursors with and without salt-KBr as a catalyst: A comparative study

The in situ doping of tungsten disulfide (WS2) monolayers with Niobium (Nb) atoms was obtained through the atmospheric pressure chemical vapor deposition (APCVD) method by controlling the Nb2O5 and WO3 precursors mass ratios. Samples were prepared employing the same growth parameters with and without the use of KBr salt as a catalyst. In both cases, the Nb incorporation quenches the luminescence intensity of the doped samples, and it depends on the Nb2O5:WO3 mass ratio. X-ray photoelectron spectroscopy (XPS) measurements were performed, and the observed redshift at the Fermi level indicated p-type doping. Nb-doped WS2 monolayers synthesized without the use of the catalyst have lower defect density, as revealed by a careful Raman analysis, and are free of agglomerates on their monolayers’ basal plane. The use of KBr as the catalyst increases the average crystal size but also increases the disorder effects compared with samples prepared without the use of salt. The presence of agglomerates of impurities at the surface of doped samples was observed in samples prepared with the use of salt as a catalyst. The controlled synthesis of p-type WS2 with low defect density is essential for developing electronic and photonic devices based on WS2 material.

Chemical Aspects of Halide Perovskite Nanocrystals.

Halide perovskite nanocrystals (HPNCs) are currently among the most intensely investigated group of materials. Structurally related to the bulk halide perovskites (HPs), HPNCs are nanostructures with distinct chemical, optical, and electronic properties and significant practical potential. One of the keys to the effective exploitation of the HPNCs in advanced technologies is the development of controllable, reproducible, and scalable methods for preparation of materials with desired compositions, phases, and shapes and low defect content. Another important condition is aquantitative understanding of factors affecting the chemical stability and the optical and electronic properties of HPNCs. Here we review important recent developments in these areas. Following a brief historical prospective, we provide an overview of known chemical methods for preparation of HPNCs and approaches used to control their composition, phase, size, and shape. We then review studies of the relationship between the chemical composition and optical properties of HPNCs, degradation mechanisms, and effects of charge injection. Finally, we provide a short summary and an outlook. The aim of this review is not to provide a comprehensive summary of all relevant literature but rather aselection of highlights, which, in the subjective view of the authors, provide the most significant recent observations and relevant analyses.

Laser Powder Bed Fusion of Hard‐Phase Containing Co‐Base Alloy

This work considers the processing of the hard‐phase containing CoCrW‐alloy Celsit F using powder bed fusion‐laser beam/metal (PBF‐LB/M), whereby a suitable process window for producing dense parts having a low‐defect density is determined. Several cuboid specimens are manufactured by varying the exposure parameters (laser power, hatch distance, scanning speed). With the help of quantitative image analysis, the samples are evaluated regarding crack density and porosity, and optimal exposure parameters are derived. Dense samples with a low defect density can be produced if the energy density is 60–70 J mm−3 and the base‐plate is preheated to 800 °C. Choosing lower energy densities leads to increased pore formation, whereas higher energy densities result in increased ablation and cracking. With a view to a later application in which additively manufactured hot work tools are made of Celsit F, the possibility of introducing internal cavities as potential cooling channels is considered. It can be shown that the hardness sideways is lower than above and below the cavity due to a changed microstructure and locally different heat dissipation. The results of this work give a first guideline for the PBF‐LB/M‐processing of wear‐resistant CoCrW alloys with a high hard phase volume content to tools for hot working.

Reconstruction of Broad Lower Lip Defects Using Karapandzic-Type Flaps.

Reconstruction of lower lip defects is challenging because of the functional and aesthetic demands of the lower face. We review the functional and aesthetic outcomes of the Karapandzic-type flaps for reconstructing lower lip defects. A retrospective review of patients who underwent repair using Karapandzic-type flaps. Fifty patients with lower lip defects ranging from 20% to 95% (mean 59.2% ± 20%) were included. Eighteen patients (36%) were repaired using a bilateral flap, and 32 (64%) were reconstructed using a unilateral flap design. All patients had preservation of oral competency and a satisfactory aesthetic result. No patient complained of microstomia. A complication rate of 8% was noted ( n = 4) with postoperative wound infection and small areas of dehiscence. There was no statistically significant difference in complication rates in patients older than 75 years, in patients with a history of head/neck radiation, or in defects greater than 70% of lower lip breadth. Karapandzic-type flaps are versatile and reliable for the reconstruction of a broad range of lower lip defects. This one-stage procedure can produce superior functional and aesthetic results as compared with other local and distant flaps with minimal risk of functional microstomia.

Magnetoresistance properties in nickel-catalyzed, air-stable, uniform, and transfer-free graphene

A transfer-free graphene with high magnetoresistance (MR) and air stability has been synthesized using nickel-catalyzed atmospheric pressure chemical vapor deposition. The Raman spectrum and Raman mapping reveal the monolayer structure of the transfer-free graphene, which has low defect density, high uniformity, and high coverage (>90%). The temperature-dependent (from 5 to 300 K) current–voltage (I–V) and resistance measurements are performed, showing the semiconductor properties of the transfer-free graphene. Moreover, the MR of the transfer-free graphene has been measured over a wide temperature range (5–300 K) under a magnetic field of 0 to 1 T. As a result of the Lorentz force dominating above 30 K, the transfer-free graphene exhibits positive MR values, reaching ∼8.7% at 300 K under a magnetic field (1 Tesla). On the other hand, MR values are negative below 30 K due to the predominance of the weak localization effect. Furthermore, the temperature-dependent MR values of transfer-free graphene are almost identical with and without a vacuum annealing process, indicating that there are low density of defects and impurities after graphene fabrication processes so as to apply in air-stable sensor applications. This study opens avenues to develop 2D nanomaterial-based sensors for commercial applications in future devices.

Efficiency improvement of thin film CuIn1-xGaxSe2 structure for solar cells applications

In this paper, the CuInGaSe2 based solar cell optimization has been established. We have simulated the structural strain effect. The effect of gallium concentration on the optical properties and the quantum external efficiency EQE was investigated. We also optimized the concentration x at low defect densities. The optimal gallium concentration is 0.30. We obtained an efficiency of the CuIn0.70Ga0.30Se2 absorber solar cell around 24% with a strain ɛ = 0.64% and material defects densities equal to 1.2x1015cm−3. This work has been validated by theoretical and experimental studies. This study allows us to find a compromise between concentration x and defect concentrations in order to improve the performance and high efficiency of the solar cell.

Controlling surface morphology of Ag-doped ZnO as a buffer layer by dispersion engineering in planar perovskite solar cells

In recent years, the power conversion efficiency (PCE (%)) of perovskite solar cells (PSCs) has improved to over 26%. To enhance the photovoltaic properties of PSCs, several materials for the electron transport layer (ETL) have been investigated. Zinc oxide (ZnO) is a significant ETL due to its high electron mobility and optical transparency in PSCs. As a result of various deposition methods, ZnO ETL can be processed at low temperatures. On the other hand, based on several studies, metal-doped ZnO can facilitate electron transfer, thereby improving the performance of un-doped ZnO ETL-based PSCs. Here, to improve the PCE (%) and long-term stability of un-doped ZnO ETL-PSCs, silver (Ag)-doped ZnO 1wt% as a buffer layer is examined. In this paper, with the addition of an organic solvent (ethanol) to the dispersion of Ag-doped ZnO 1 wt% nanoparticles (NPs) in deionized (DI) water, the morphology of the buffer layer (Ag-doped ZnO 1 wt%) can be controlled. This approach focuses on reducing the wettability of the ZnO/Ag-doped ZnO 1 wt% bilayer ETLs and enhancing the stability of un-doped ZnO ETL-PSCs. According to the results, the ZnO/H2O-ethanol mixtures-Ag-doped ZnO 1 wt% bilayer ETL leads to the formation of high-quality perovskite with low defects, reducing the recombination rate, and long-term stability of un-doped ZnO ETL-PSCs in ambient conditions.

Origin of linear magnetoresistance in Bi2Te3 topological insulator: Role of surface state and defects

Connection between topological surface states (TSS) and large linear magnetoresistance (LMR) is established in tetradymite Bi2Te3 through tuning of native defects. Thorough analysis of temperature dependent synchrotron X-ray diffraction data quantifies 0-D, 1-D and 2-D defect concentrations. Plausible variation of antisite defects is explained via carrier concentration data. Resistivity data divulge contribution of mixed bulk and surface states in the synthesized samples. High Fermi velocity (∼106 ms−1) and low Fermi energy (∼14 meV) of carriers are obtained. Lower defect concentration sample emerges with high magnetoresistance (MR) and higher mobility. Weak antilocalization (WAL) effect, signature of TSS, is revealed from MR. Large (80%), non-saturating LMR along with ultrahigh mobility (∼1 m2V−1s−1) in Bi2Te3 supports the presence of TSS. Magnetoconductance data are fitted with Hikami-Larkin-Nagaoka equation, obtaining further insight on WAL effect. In addition, extracted parameters like disorder correlation length and coherence length explicate the role of defect density on LMR.

Reconstruction of Full-Thickness Eyelid Defects Following Tumor Resection: The Bucket Handle Modification.

To describe a modified approach for full-thickness lower eyelid defect reconstruction. This is a retrospective review of 5 patients with large full-thickness lower eyelid defects after tumor resection requiring reconstruction. For these lower eyelid defects, a lateral-based or superior-based tarsoconjunctival pedicle flap from the upper eyelid was used to rebuild the posterior lamella. In all cases, the anterior lamella was supplied from an adjacent myocutaneous flap in a bucket handle configuration. Data collection included tumor type and location, size of eyelid defect, presence of canalicular involvement, postoperative eyelid position, patient satisfaction, and complication rates. Five eyelids of 5 patients underwent Mohs micrographic excision of basal cell carcinoma followed by reconstruction with a bucket handle flap. Age range was 68 to 96 years old (mean of 81y). Five patients presented with lower eyelid involvement. The defect size ranged from 80% to 100% of the eyelid. Three patients had canalicular involvement and required bicanalicular nasolacrimal stent placement. After reconstruction, all patients showed good eyelid apposition to the globe with excellent esthetic outcome. No revision procedures were done. Average follow-up time was 13 months (range of 8 to 21mo). The bucket handle flap for full-thickness eyelid reconstruction is a simple technique that allows for preservation of all anatomical layers of the anterior lamella. This technique shows promising functional and esthetic outcomes.