High‐Performance Flexible Nanostructured Silicon Solar Modules with Plasmonically Engineered Upconversion Medium

Abstract

optoelectronics. [ 1,2 ] Advantages including reduced materials consumption, relaxed requirements of materials purity, and ability to form large-area devices on unlimited classes of module substrates make them particularly useful as building blocks for realizing high-effi ciency, low-cost photovoltaic systems. [3][4][5] The photovoltaic performance of ultrathin silicon solar cell is, however, inherently limited by incomplete absorption of longer wavelength photons near its bandgap. [ 6,7 ] While light trapping methods based on various diffractive and/ or refl ective optical elements can greatly help to improve the absorption of optically thin silicon, [8][9][10][11][12][13] complementary means to additionally capitalize on such low energy photons are desirable to further improve the performance of ultrathin silicon solar cells. In particular, spectral upconversion, a concept proposed for addressing the sub-bandgap transparency of solar cells, [14][15][16][17][18][19][20][21] is an attractive approach that provides an additional pathway to enhance the quantum effi ciency of above-bandgap longer wavelength photons by converting them into high energy photons that can be more strongly absorbed by the ultrathin silicon. One of key challenges for the practical application of spectral upconversion in photovoltaics (PVs), however, is that the intensity of natural sunlight in relevant wavelengths (i.e., near-infrared) is often too weak to yield meaningful effects of upconversion. [22][23][24] In this regard, recent advances in light manipulation using metallic nanostructures, A type of composite photovoltaic system that can improve the absorption of longer wavelength photons for ultrathin silicon solar cells is presented by synergistically exploiting spectral upconversion and plasmonic light manipulation under a reconfi gurable platform where individual module components can be independently optimized and strategically combined by printing-based deterministic materials assemblies. The ultrathin (≈8 µm) nanostructured silicon solar cells are embedded in a thin polymeric medium containingNaYF 4 :Yb 3+ ,Er 3+ nanocrystals, coated on a plasmonically engineered substrate that incorporates hybrid nanostructures of cylindrical nanoholes and truncated-cone-shaped nanoposts. Both excitation and emission processes of upconversion luminophores are signifi cantly enhanced by combined effects of surface plasmon resonance to amplify the light intensity at the excitation wavelength as well as to facilitate the far-fi eld outcoupling at the emission wavelengths, respectively. The performance of the integrated solar module is improved by ≈13% compared to devices on a nanostructured plasmonic substrate without luminophores due to collective contributions from plasmonically enhanced spectral upconversion, together with effects of waveguiding and fl uorescence of NaYF 4 :Yb 3+ ,Er 3+ . Detailed studies on optical properties of engineered plasmonic nanostructures and device performance in both experiments and numerical modeling provide quanti...

Advances in plasmon‐enhanced upconversion luminescence phenomena and their possible effect on light harvesting for energy applications

“…The use of low‐power sunlight for UC was demonstrated by Yoon and coworkers, who fabricated silicon solar cells with plasmonically engineered UC layers . This work presented the first large enhancement seen with the use of plasmon‐enhanced UC layers for photovoltaics.…”

“…Contour plots of electric field intensity profiles for a plain Ag (first column), nanoholes (second column), nanoposts (third column), and hole/post hybrid nanostructures (fourth column) of Ag under normally incident illumination at wavelengths of 980 (top), 660 (middle), and 540 nm (bottom), respectively, at the optimal geometry of each configuration at p hole (or post) = 700 nm (i.e., D hole = 300 nm, h hole = 340 nm for nanoholes; D post = 450 nm, h post = 80 nm for nanoposts; D hole = 540 nm, h hole = 440 nm, D post = 330 nm, h post = 120 nm for hybrids). (Source from Ref . )…”

“…A 968‐nm CW laser (12 W cm −2 ) was illuminated at an incidence angle of ≈ 5°, and the emitted light was collected by a fiber optic‐connected spectrometer. (Source from Ref . )…”

Ultra‐Wideband Multi‐Dye‐Sensitized Upconverting Nanoparticles for Information Security Application

“…Optimized interligand energy transfer on the nanoparticle surface by controlling the spacing (total number of ligands on a UCNP) and ratio of the dye ligands maximizes the energy migration efficiency. [13,14] However, well-known UCNPs, such as those based on a NaYF 4 matrix with lanthanide ion (e.g., Yb 3+ ), [15,16] have a narrow and weak absorption band at ≈975 nm by the quantized electron transition between the energy levels of 2 F 7/2 and 2 F 5/2 in the Yb 3+ ion. Although the destruction of the transient electronics can be achieved by addition of triggering materials, [26] the photo-triggered destruction based on a photo-sensitive solid state film provides a more facile erasure route of the data in RRAM device, which is great advantage in the mobile applications.…”

“…[1,2] Because of their high photochemical stability, sharp emission bandwidth, and large anti-Stokes shift (up to several hundred nanometers), these UCNPs have been highlighted as key materials in several photonic applications including biomedical imaging probes, [3][4][5][6] in vivo therapeutics, [7][8][9][10] optogenetics, [11,12] and optoelectronic devices. [13,14] However, well-known UCNPs, such as those based on a NaYF 4 matrix with lanthanide ion (e.g., Yb 3+ ), [15,16] have a narrow and weak absorption band at ≈975 nm by the quantized electron transition between the energy levels of 2 F 7/2 and 2 F 5/2 in the Yb 3+ ion. [17,18] The extension of their applications in emerging fields, including multi-modal imaging and high-performance electronics/ optoelectronics, have been oftentimes limited by their narrow absorption bandwidth in the near-infrared (NIR) range and weak photo-absorption.…”