Plasmonic Light Trapping in Thin-film Silicon Solar Cells with Improved Self-Assembled Silver Nanoparticles

Abstract

Plasmonic metal nanoparticles are of great interest for light trapping in thin-film silicon solar cells. In this Letter, we demonstrate experimentally that a back reflector with plasmonic Ag nanoparticles can provide light-trapping performance comparable to state-of-the-art random textures in n-i-p amorphous silicon solar cells. This conclusion is based on the comparison to high performance n-i-p solar cell and state-of-the-art efficiency p-i-n solar cells deposited on the Asahi VU-type glass. With the plasmonic back reflector a gain of 2 mA/cm(2) in short-circuit current density was obtained without any deterioration of open circuit voltage or fill factor compared to the solar cell on a flat back reflector. The excellent light trapping is a result of strong light scattering and low parasitic absorption of self-assembled Ag nanoparticles embedded in the back reflector. The plasmonic back reflector provides a high degree of light trapping with a haze in reflection greater than 80% throughout the wavelength range 520-1100 nm. The high performance of plasmonic back reflector is attributed to improvements in the self-assembly technique, which result in a lower surface coverage and fewer small and irregular nanoparticles.

Midinfrared Surface Plasmons in Carbon Nanotube Plasmonic Metasurface

“…Plasmonic structures are used in sensing [1,2], nonlinear optics [3,4], and nanophotonics [5]. Since SP modes are characterized by the large enhancement of the electromagnetic field, plasmonic metasurfaces are being investigated to improve light harvesting efficiency in solar cells [6][7][8] and to overcome low intrinsic absorption of monolayer graphene [9][10][11][12][13]. In plasmonic structures, the field is primarily localized in the dielectric adjacent to metal, which results in an additional absorption in the vicinity of SP resonance [14,15].…”

Photonic Structures for Light Trapping in Thin Film Silicon Solar Cells: Design and Experiment

“…For n-i-p TFSCs, light-trapping primarily occurs owing to the textured back reflector. In the last few years, a variety of novel light-trapping concepts and structures, including low pressure chemical vapor deposited (LPCVD) -ZnO [14], chemically-etched ZnO [15], textured glass [13], modulated surface textures [16], plasmonic light-trapping [17,18], honeycomb pattern substrates [19] and photonic structures [20][21][22][23][24][25][26][27][28][29][30][31], have been widely studied and utilized to improve the solar cell performances. Recently, a dielectric one-dimensional photonic crystal (1D-PC), which is formed by periodically stacking high refractive index (high-n) layers and low refractive index (low-n) layers [25][26][27], also was regarded as a highly promising light-trapping concept.…”

The role of front and back electrodes in parasitic absorption in thin-film solar cells

“…For this device, light trapping strategies are applied for a broad wavelength range of the solar spectrum, covering the near infrared (NIR) range between 600 nm and 1100 nm. The absorption coefficient of µc-Si:H silicon being weak in the NIR, efficient light trapping (typically via nanotextured interfaces) is mandatory to achieve large currents [7][8][9][10][11][12][13][14]. Yet, in the presence of a very efficient light-trapping scheme, parasitic absorption (A P ) due to the non-photoactive layers (such as the doped layers, the electrodes and the back a e-mail: mathieu.boccard@epfl.ch reflector) is also increased compared to a flat cell configuration [6,[15][16][17].…”