Numerical simulations of light-extraction efficiencies of light-emitting diodes on micro and nanopatterned sapphire substrates

Micro & nano letters

article

Hao Cui¹  Si-Hyun Park¹ 

[1] Department of Electronic Engineering, Yeungnam University

关键词: gallium compounds;    III-V semiconductors;    wide band gap semiconductors;    light emitting diodes;    semiconductor device models;    finite difference time-domain analysis;    numerical simulations;    light-extraction efficiencies;    micropatterned sapphire substrates;    nanopatterned sapphire substrates;    gallium nitride-based light-emitting diodes;    LED;    three-dimensional finite-difference time-domain method;    hexagonal arrays;    cone-shaped patterns;    pattern array pitch;    pattern fill factor;    pattern height;    geometrical parameters;    GaN;    Al2O3;   

DOI  :  10.1049/mnl.2014.0373

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Introduction: Optic nerve sheath diameter (ONSD) using ocular ultrasound is increasingly used now a days as noninvasive means of detecting raised intracranial pressure. We conducted a cross‐sectional, observational study to assess its validity, optimal cutoff limit and inter‐observer variability in our ICU patients. Methodology: The adult patients admitted to our ICU during six month interval (Jan 2014‐June 2014) were enrolled for the study. The exclusion criteria were patients breathing spontaneously, presence of hyperthyroidism, optic nerve tumor, neuritis, glaucoma and orbital fracture. The patients were divided into two groups. Group I – those having increased ICP clinically or as per radiological findings. Group II – patients having no features of raised ICP. A linear probe with a frequency 13‐7 MHz, SonositeTM USA, was used to measure ONSD by two blinded, experienced investigators. Mean of three readings was taken. The entire data was compiled and analyzed applying appropriate statistical tests.

【 授权许可】

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