Browsing by Author "Huang, Hsin"

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Observation of strain-induced phonon mode splitting in the tetragonal hybrid halide perovskite
(2017-11-01)
Ahn, Hyeyoung
;
Huang, Hsin
;
Hsieh, Meng-I
;
Li, Ming-Hsien
;
Chen, Peter
We report the structural and low-frequency vibrational properties of methylammonium lead-iodide (MAPbI(3)) perovskites studied by terahertz spectroscopy. The characteristic low-frequency mode splitting is observed in room-temperature tetragonal MAPbI(3) films grown on Si, and the frequencies of split modes are found to coincide with those of orthorhombic phases. The strain arising from the symmetry and lattice mismatch against the substrates is responsible for the local distortion of inorganic cages and results in the mode-splitting. The use of a mesoporous TiO2 interlayer effectively reduces the strain at the perovskite-substrate interface and induces larger grain growth and the improvement of structural ordering in the tetragonal MAPbI(3) films. (C) 2017 The Japan Society of Applied Physics
Using a Low Fluence Q-Switched 532/1064-nm Nd:YAG Laser for Facial Skin Depigmentation in Asian Patients Outcome and Complication Profile Analysis
(2016-08)
Shen, Jen-Hsiang
;
Chang, Chang-Cheng
;
Chen, Yu-Tsung
;
Hsih, Chao-Jen
;
Huang, Hsin
Background and Objectives: Low fluence Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers are widely applied for facial depigmentation. Nonetheless, few reports analyze the general outcome, complications, of single and combined therapy of 532/1064-nm Nd: YAG lasers in Asian patients with Fitzpatrick type IV skin. Study Design/Materials and Methods: We retrospectively reviewed all consecutive patients who completed 5 consecutive sessions at 1-month intervals of treatment with 1064-nm (spot size: 5-7 mm, 1.5-2.0 J/cm(2)) or combined with 532-nm (spot size, 2-3 mm; 0.5-1.5 J/cm(2)) Nd: YAG laser (Laseroptek, Korea) from October 2011 to March 2013. The patients, laser surgeon, and 3 blinded reviewers assessed the outcomes and complications. Improvement was graded as follows: 1, 0%-25%; 2, 26%-50%; 3, 51%-75%; 4, 76-90%; and 5, greater than 90%. Postinflammatory hyperpigmentation (PIH) was documented according to the severity (1, slight; 2, moderate; 3, severe; and 4, extreme). Other post-laser side effects were also documented (eg, scaling, dryness, erythema, and pruritus). Results: Four male patients and 37 female patients were included with a mean age of 38.5 years (SD, 10.1 years). There were no significant differences on patients\', surgeon\'s, or blinded reviewers\' improvement gradings. (4.11 +/- 0.62 vs 4.30 +/- 0.46, P = 0.54; 3.88 +/- 0.66 vs 3.89 +/- 0.31, P = 0.50; 3.30 +/- 0.69 vs 3.74 +/- 0.38, P = 0.34). Transient minor side effect occurred as follows: erythema in 9 (22%), pruritus in 7 (17%), dryness in 6 (15%), and scaling in 6 (15%). There was no risk difference in these side effects between groups. The PIH scores were slight in 10 patients (4 in single and 6 in combined), severe in 4 (3 in single and 1 in combined), and extreme in 1 (single therapy). The PIH incidence also did not differ (33.3%, 35.3%; P = 0.58). Conclusions: We reported satisfactory outcomes after low-fluence Q-switched sole 1064-nmor combined 532/1064-nm therapy. The outcome and complication profiles did not differ between the groups. The PIH incidence was not low, but usually transient. The incidence of severe or extreme PIH was rare.