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Light trapping is particularly important because of the desire to produce low-cost solar cells with the thinnest possible photoactive layers. Herein, along the research line of “ optimization → fabrication → characterization → application ”, concave arrays were incorporated into amorphous silicon thin-film solar cell for lifting its photoelectric conversion efficiency. In advance, based on rigorous coupled wave analysis method, optics simulations were performed to obtain the optimal period of 10 μ m for concave arrays. Microfabrication processes were used to etch concave arrays on glass, and nanoimprint was devoted to transfer the pattern onto polymer coatings with a high fidelity. Spectral characterizations prove that the concave-arrays coating enjoys excellent the light-trapping behaviors, by reducing the reflectance to 7.4% from 8.6% of bare glass and simultaneously allowing a high haze ratio of ∼ 70% in 350–800 nm. Compared with bare cell, the concave-arrays coating based amorphous silicon thin-film solar cell possesses the improving photovoltaic performances. Relative enhancements are 3.46% and 3.57% in short circuit current and photoelectric conversion efficiency, respectively. By the way, this light-trapping coating is facile, low-cost and large-scale, and can be straightforward introduced in other ready-made solar devices. [ABSTRACT FROM AUTHOR]

A novel frosted glass with regular pit array texture has been prepared using a micro-fabrication process. The aspect ratio of the pit array can be controlled by changing the etching time of HF or adjusting the design period of lithography mask. Comparing with traditional frosted glass, this frosted glass exhibits lower reflectance and higher transmittance. The average light reflectance of the fabricated forsted glass with the aspect ratio of ∼0.3 is reduced by 40%, and the transmittance is increased by 10%. The optical performance can be changed via adjusting the aspect ratio of pit array. The larger aspect ratio, the lower light reflection, the higher transmission and haze. [ABSTRACT FROM AUTHOR]

Fabrication of highly ordered nanostucture arrays on desirable substrate has great potential applications in optoelectronics, photocatalysis and biological sensors. A simple but efficient fabrication method for producing ordered Au nanocone arrays on glass through using ultrathin alumina membranes (UTAMs) as evaporation masks was detailed described in this report. Meanwhile, the surface plasmon resonance (SPR) property of these highly ordered Au nanocone arrays was characterized by absorption spectrum with a peak position located at 618 nm. The simulated spatial distribution of the electric field revealed a strong enhancement of electromagnetic field in the vicinity of Au nanocones, which provided a good explanation on the enhanced Raman spectrum of Rhodamine 6G. Futhermore, because of trapping air bubble into the valleys, an increasing hydrophobicity of surface patterned by Au nanocone arrays was achieved. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports a study about how to enhance the performance of thin film Si solar cells. Periodic microhemisphere hole (PMHH) arrays with a period of 10μm and a depth of ~4μm were made on the glass wafers. We found that the PMHH arrays can trap light via testing the transmittance of glass with PMHH arrays. Comparing with the original cell, the thin film Si solar cell covered by this kind of PMHH arrays glass is different from the following two perspectives: the short-circuit current (J sc) increased by 7.5% and the conversion efficiency (Eff) enhanced by 5.2%. The design based on light trapping scheme on the external of cell is feasible and worth promoting. [Copyright &y& Elsevier]

We report the preparation of ZnO quantum dot hybrid luminescent resists for nanoimprint lithography. Photoluminescence spectra indicate that ZnO QDs@AMONIL have a significant increase in the luminescent intensity, an obvious blue-shift of emission peak and the Stoke's shift, revealing that ZnO QDs@AMONIL have dramatic luminescent property change instead of inhibiting or only preserving the optical properties of pure ZnO QDs. The fabrication of two-dimensional (2D) photonic crystal structure on the ZnO QDs@AMONIL by UV-based nanoimprint lithography is demonstrated at last, which confirms the luminescent ZnO QDs@AMONIL reliable processing capabilities in wavelength-scale and envisions its promising applications in the optoelectronic micro-/nanodevices. [ABSTRACT FROM AUTHOR]

Abstract: A novel size reduction process using electron beam lithography (EBL) combining with wet etching technique is developed as a possible solution for producing large area and low cost nanopattern stamp for UV-based nanoimprint lithography (UV-NIL). In the first step, a microstructure stamp with 1.4μm periodical pore array and aspect ratio of 1:1 was formed over a 1inch2 area on a quartz substrate. This process was carried out using common electron beam lithography (EBL) equipment, which was easily available in the modern integrated circuits (IC) semiconductor factory. Afterwards, with a controlled wet etching technique, the pore array was changed into tip patterns with the line width below 100nm and the period keeping as before. The uniformities and nanopattern accuracies were investigated to identify its possibility as a UV-NIL stamp by AFM and SEM. Finally, as a demonstration, the as obtained stamp was used as a positive stamp to replicate the nanotips into UV-curable resist successfully by a UV-NIL process. The method developed for the mold of nanoimprint lithography would be a simple and low price approach to fabricate large area UV-NIL stamp and the nanotip array structures would be widely used in two dimensional (2D) photonic crystal application. [Copyright &y& Elsevier]