We describe an ultrathin solar cell architecture that combines the benefits of both plasmonic photovoltaics and traditional antireflection coatings. Spatially resolved electron generation rates are used to determine the total integrated current improvement under AM1.5G solar illumination, which can reach a factor of 1.8. The frequency-dependent absorption is found to strongly correlate with the...

New and optimized metal-oxide thin films for both transparent-conductor and antireflection coatings have the potential to significantly improve photovoltaic devices. One approach to this task of discovery and improvement is to use a parallel optimization, i.e., a combinatorial, approach. Using internal seed funds, we have developed the initial deposition, characterization and analysis tools nec...

Recent investigations have added to and refined the understanding of the behavior of broadband antireflection coating designs and provided further guidance for achieving more nearly optimal designs. The ability to optimize designs wherein the overall optical thickness of the design is constrained to a specific value has allowed this investigation. A broader bandwidth than previously reported ha...

We report the first results of self-assembled nanostructures using colloids for antireflection optical coatings. Two-dimensional (2D) periodic nano-structures were made by using self-assembled 2D colloidal crystals on top of a transparent substrate. An atomic force microscope was used to evaluate the quality of the nanostructure. The feature size of the structures was around 105 nm. This sub-wa...

Examining spectral regions outside of the band where an antireflection coating is specified can aid in finding optimal design solutions. The reflectance versus wavenumber plots at low frequencies indicate the overall thickness of the design. These plots also point to whether the design will provide the minimum possible average reflectance in the specified band. It has been discovered that these...

The application of a few basic principles, some empirical data, and experience is applied to estimate the average residual reflection expected in an AR coating as a function of bandwidth, wavelength, overall thickness, substrate index, available coating materials, and number of layers. This can be a useful tool for not only the thin film designer but also the non-designer or system engineer to ...

A technique connecting a scalar wide-angle finitedifference beam-propagation method(FD-BPM) with a scalar finite-difference time-domain method (FD-TDM) is systematically described and used to analyze a lensed coreless fiber. The propagating field and its phase distribution are calculated to demonstrate the phase adjustment effect of the lens. The power concentration due to the lens is evaluated...

The mid-infrared transmission through a 3.7 mm period, twodimensional sub-wavelength Au metallic hole array integrated on a GaSb/InAs strained layer superlattice nBn photodetector is measured. The surface plasmon-polariton excitation on the Au film induces a peak transmission in the 200 K detector response at 4.2 mm. This transmission is enhanced threefold by the insertion of a SiNx layer betwe...

Lithography, the fundamental fabrication process of semiconductor devices, is playing a critical role nowadays in the fabrication of microand nano-structures especially for the realization of micro-electro-mechanical systems (MEMS), microfluidic devices, photonic crystals, photonic integrated circuits, micro-optics, and plasmonic optoelectronic devices. These devices have various practical appl...

An electrochemical etching technique has been developed that provides continuous control over the porosity of a porous silicon layer as a function of etching depth. Thin films with engineered porosity gradients, and thus a controllable gradient in the index of refraction, have been used to demonstrate broadband antireflection properties on silicon wafer and solar cell substrates. A simulation w...