Multi-resonant silver nano-disk patterned thin film hydrogenated amorphous silicon solar cells for Staebler-Wronski effect compensation

Abstract

We study polarization independent improved light trapping in commercial thin film hydrogenated amorphous silicon (a-Si:H) solar photovoltaic cells using a three-dimensional silver array of multi-resonant nano-disk structures embedded in a silicon nitride anti-reflection coating (ARC) to enhance optical absorption in the intrinsic layer (i-a-Si:H) for the visible spectrum for any polarization angle. Predicted total optical enhancement (OE) in absorption in the i-a-Si:H for AM-1.5 solar spectrum is 18.51% as compared to the reference, and producing a 19.65% improvement in short-circuit current density (JSC) over 11.7 mA/cm 2 for a reference cell. The JSC in the nano-disk patterned solar cell (NDPSC) was found to be higher than the commercial reference structure for any incident angle. The NDPSC has a multi-resonant optical response for the visible spectrum and the associated mechanism for OE in i-a-Si:H layer is excitation of Fabry-Perot resonance facilitated by surface plasmon resonances. The detrimental Staebler-Wronski effect (SWE) in a-Si:H solar cell can be minimized by the additional OE in the NDPSC and self-annealing of defect states by additional heat generation, thus likely improving the overall stabilized characteristics of a-Si:H solar cells.

Limitations of ultra-thin transparent conducting oxides for integration into plasmonic-enhanced thin-film solar photovoltaic devices

“…This deposition rate The results simulated using COMSOL show how the useful optical absorption in the active regions of plasmonic PV devices varies with TCO type and thickness. Theoretically, at small film thicknesses Ohmic losses decrease and useful optical absorption increases [15] was determined by depositing for a set amount of time and measuring the resulting film thickness using stylus profilometry (Veeco Dektak 150).…”

“…TCOs such as the most established indium tin oxide (ITO), aluminum-doped zinc oxide (AZO) and zinc oxide (ZnO) are standard integral materials in current thin-film solar PV devices [15][16][17][18]. Bulk material properties for common TCOs including ITO have been well researched and documented for different processing conditions and substrates [15,16,[19][20][21][22][23]; however, this is not the case for ultra-thin TCOs. The few exceptions include Sychkova et al [24], who reported both optical and electrical properties of 9-80 nm ITO films deposited by pulsed DC sputtering varied with thickness and showed a general increase in resistivity with decrease in film thickness [24].…”

“…1a [15]. These simulation results are used to guide the experimental work which investigated both optical and electrical properties of ultra-thin (10 nm on average) films simultaneously deposited on both glass and silicon substrates (with a thermally grown oxide layer.…”

“…For example, simulations by Vora et al showed a 19.65 % increase in short circuit current (J SC ) for nanocylinder patterned solar cell (NCPSC) in which the ITO layer thickness was kept at 10 nm to minimize the parasitic Ohmic losses and simultaneously act as a buffer layer while helping to tune the resonance for maximum absorption [14]. TCOs such as the most established indium tin oxide (ITO), aluminum-doped zinc oxide (AZO) and zinc oxide (ZnO) are standard integral materials in current thin-film solar PV devices [15][16][17][18]. Bulk material properties for common TCOs including ITO have been well researched and documented for different processing conditions and substrates [15,16,[19][20][21][22][23]; however, this is not the case for ultra-thin TCOs.…”

Review of near-field optics and superlenses for sub-diffraction-limited nano-imaging

“…[2][3][4][5][6] This resolution was extended further by apertureless SNOM systems, which employed a nanoscale scattering probe in the near-field instead of a subwavelength aperture. [7][8][9][10][11][12][13][14] At the turn of the new millennium, imaginative new approaches for controlling electromagnetic waves began to appear for imaging, [15][16][17][18][19][20][21][22][23] photovoltaics, [24][25][26] quantum information processing and simulations, [27][28][29][30][31] wireless communications, 32,33 and novel optical materials, [34][35][36][37][38][39][40] among many others. The advent of metamaterials with simultaneously negative permittivity and permeability 41 brought renewed interest in the properties of left-handed materials first proposed by Veselago,42 which Pendry demonstrated could be applied to sub-diffraction-limited imaging with his "perfect lens."…”