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We integrate two dimensional hole arrays (2DHAs),a plasmonic structure, into silicon based blocked impurity band (BIB) terahertz detectors. The photoresponse of the BIB device without 2DHA covers a broad spectral range from 31 μm (9.68 THz) to 15 μm (20 THz). Although 80% of the active region is covered with a metal film in the surface plasmon (SP)-enhanced device, its absolute photoresponse is 120% higher than that of the reference device at the peak wavelength. We further find that the SP-enhanced device presents about 8-fold enhancement in comparison with the reference device at λ = 30.7 μm (9.77 THz) that is beyond the SP resonance. By an energy band model and electromagnetic field simulation, we discover that the photoresponse enhancement at both the resonance wavelength and the non-resonance wavelength is related to a strong confined electromagnetic field at the interface of the 2DHAs and active region.

Differential scanning calorimetry (DSC) was used to investigate the crystallinity of crude PVC powders and annealed PVC compounds. Crude PVC powder exhibited a broad crystallite fusion endotherm ranged from 110°C to 220°C. High degree of polymerization of PVC showed high degree of crystallinity both for powder and annealed sample under the same annealing conditions. Annealing conditions (time and temperature) had large effects on recrystallization behavior of PVC. The crystallinity of PVC decreased with increasing of DOP plasticizer content in PVC compounds, and lead to decrease of modulus and increase of average molecular weight between physical crosslinks.