ABSTRACT
Polycrystalline perovskite light-emitting diodes (PeLEDs) have shown great promise with high efficiency and easy processability. However, PeLEDs using single-cation polycrystalline perovskite emitters have demonstrated low efficiency due to defects within the grains and at the interfaces between the perovskite layer and the charge injection contact. Thus, simultaneous defect engineering of perovskites to suppress exciton loss within the grains and at the interfaces is crucial for achieving high efficiency in PeLEDs. Here, 1,8-octanedithiol which is a strong nucleophile, is used to increase the luminescence efficiency of a single-cation perovskite by suppressing non-radiative recombination within the grains of their polycrystalline emitter film as well as at their interface with an anode. The dithiol additive performs a multifunctional role in defect passivation, spatial confinement of excitons, and prevention of exciton quenching at the interface between the perovskite layer and the underlying hole-injection layer. Photoluminescence studies demonstrate that incorporating the dithiol additive significantly enhances the charge carrier dynamics in perovskites, resulting in an external quantum efficiency (EQE) of up to 23.46% even in a simplified PeLED that does not use a hole-injection layer. This represents the highest level of EQE achieved among devices utilizing polycrystalline single-cation perovskites.
ABSTRACT
BACKGROUND: For patients with trigeminal neuralgia who do not respond to medication and for whom surgical approaches are too risky, percutaneous procedures targeting the trigeminal ganglion are the current standard treatment. Percutaneous procedures are performed via the transoval approach under radiologic guidance. Identification of the foramen ovale (FO) under fluoroscopic guidance is an important part of determining the success or failure of the procedures. OBJECTIVES: Previous studies have described how to visualize the FO under fluoroscopic guidance, but those methods are limited by poor reproducibility. In this study, we have investigated how to visualize the FO clearly and easily under fluoroscopic guidance. STUDY DESIGN: Retrospective analysis. SETTING: University hospital in Korea. METHODS: Seventy-two 3-dimensional facial computed tomography scans without anatomic abnormalities of the skull base were analyzed for verifying the novel method. First, the mandibular angle and the occipital cortical line were overlapped and then turned by 15° oblique rotation using the software package. After these manipulations, the visualization of the FO was graded according to a 4-point scale (0: poor; 1: fair; 2: good; 3: excellent), and the inferior transfacial and oblique angles were measured. RESULTS: This enabled clear visualization of the FO. The mean visual grade of 54 right and 46 left FO (total 100) was 2.74 (0: poor; 1: fair; 2: good; 3: excellent). All recorded FOs had at least grade 2 visibility. LIMITATIONS: This study is lacking application in clinical practice and comparative data to the submental view. CONCLUSIONS: The mandible angle and the occipital cortex line are obvious anatomic landmarks and are visible even to nonexperienced practitioners. Therefore, our method using these anatomic landmarks can improve the reproducibility and accuracy of FO visualization. KEY WORDS: Trigeminal neuralgia, foramen ovale, trigeminal ganglion, 3-dimensional (3D) facial computed tomography (CT) scans.