In this paper, we present an ultra-fast, simple and cost-effective way-the direct peeling method (DPM)-to produce nanohairs with high aspect ratio on fluorinated ethylene propylene (FEP) films within 30 s. The FEP films with nanohair structures afford impressive demonstrations of superhydrophobicity and self-cleaning effect; the characteristics described above along with the flexibility of FEP may prove useful for solar cells and curved components in the field of biological and technological applications.

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An efficient and effective method to achieve high responsivity and specific detectivity, particularly for normal-incident quantum well infrared photodetectors (QWIPs), is proposed in this study. By combining superlattice (SL) structure, grating structures, and graphene monolayer onto traditional QWIP designs, a graphene-covered multicolor quantum grid infrared photodetector (QGIP) with improved optoelectrical properties is developed. The enhancements of the device’s responsivity and specific detectivity are about 7-fold and 20-fold, respectively, which resulted from an increase in the charge depletion region and the generation of extra photoelectrons due to graphene-semiconductor heterojunction. This method provides a potential candidate for future high-performance photodetectors.

An efficient method to modify the defect density of a gallium nitride (GaN) epi-wafer is proposed in this study. A patterned sapphire substrate (PSS) was used here acting as the medium for defect adjustment. The characteristics of yielded samples were analyzed by Raman scattering and etching pitch density (EPD) methods, which did show the improved crystal quality of GaN. Following high electron mobility transistor (HEMT) application based on the yield sample was executed, and the performances of the devices did improve as well.