Yi-Yu Lee

Performance-Enhanced Textured Silicon Solar Cells Based on Plasmonic Light Scattering Using Silver and Indium Nanoparticles

Performances of textured crystalline-silicon (c-Si) solar cells enhanced by silver nanoparticles (Ag-NPs) and indium nanoparticles (In-NPs) plasmonic effects are experimentally demonstrated and compared. Plasmonic nanoparticles integrated into textured c-Si solar cells can further increase the absorption and enhance the short-circuit current density (Jsc) of the solar cell. To examine the profile of the proposed metallic particles, the average diameter and coverage of the In-NPs (Ag-NPs) at 17.7 nm (19.07 nm) and 30.5% (35.1%), respectively, were obtained using scanning electron microscopy. Optical reflectance and external quantum efficiency response were used to measure plasmonic light scattering at various wavelengths. Compared to a bare reference cell, the application of In-NPs increased the Jsc of the cells by 8.64% (from 30.32 to 32.94 mA/cm2), whereas the application of Ag-NPs led to an increase of 4.71% (from 30.32 to 31.75 mA/cm2). The conversion efficiency of cells with embedded In-NPs (14.85%) exceeded that of cells with embedded Ag-NPs (14.32%), which can be attributed to the broadband plasmonic light scattering of the In-NPs.

Light-trapping performance of silicon thin-film plasmonics solar cells based on indium nanoparticles and various TiO2 space layer thicknesses

Thin-film solar cells have the potential to substantially reduce the material cost of photovoltaic devices. However, to increase the amount of light absorbed in the thin active layer, light trapping is a critical concern in developing thin-film solar cells. In this study, we investigated the suitability of using localized surface plasmons of indium nanoparticles (In NPs) on TiO2 space layers of various thicknesses to enhance the absorption of silicon (Si) thin-film solar cells. The experimental results demonstrated how the combined effects of the incident light plasmonics scattering, surface passivation, and antireflection of In NPs affect the photovoltaic performance of the TiO2 space layer. The optical reflectance, dark current, photocurrent, and external quantum efficiency were measured and compared. Compared with bare-type Si thin-film solar cells, the proposed cells with In NPs on a 59.5-nm-thick TiO2 space layer demonstrated a short-circuit current enhancement of 45.7% (from 2.56 to 3.73 mA) and a conversion efficiency enhancement of 36.2% (from 7.56 to 10.3%).

Electrical and optical performance of plasmonic silicon solar cells based on light scattering of silver and indium nanoparticles in matrix-combination.

This study demonstrates the efficacy of combining a matrix of silver nanoparticles (Ag-NPs) with indium nanoparticles (In-NPs) to improve the electric and optical performance of plasmonic silicon solar cells. We examined the excitation of localized surface plasmons of Ag-NPs and In-NPs using surface enhanced Raman scattering measurements. Optical reflectance and external quantum efficiency (EQE) measurements demonstrate that the light scattering of Ag-NPs at short wavelengths can be improved by surrounding them with In-NPs. This also leads to high EQE band matching in the high energy band of the AM1.5G solar energy spectrum. Impressive improvements in optical reflectance and EQE response were also observed at short wavelengths. Cells with a matrix of Ag-NPs (20% surface coverage) surrounded by In-NPs (80% surface coverage) increased the overall efficiency of the cell by 31.83%, as confirmed by photovoltaic current density-voltage characterization under AM 1.5 G illumination.

External quantum efficiency and photovoltaic performance of silicon cells deposited with aluminum, indium, and silver nanoparticles

In this study, the plasmonic light scattering of aluminum (Al), indium (In), and sliver (Ag) nanoparticles (NPs) deposited on silicon solar cells was demonstrated. For comparison, the dimensions of all NPs were maintained at 17–25 nm with a coverage of approximately 30–40% through the control of film deposition and thermal annealing conditions. Absorbance and surface plasmon Raman scattering were used to examine the different localized surface plasmon resonances (LSPRs) of the proposed NPs. Optical reflectance, external quantum efficiency (EQE) response, and photovoltaic current density–voltage characteristics under AM 1.5G illumination were used to confirm the contribution of the plasmonic light scattering of the NPs. The conversion efficiencies of the solar cells with Al, In, and Ag NPs increased 1.21-, 1.23-, and 1.17-fold, respectively, compared with that of the reference bare Si solar cell. The EQE response and photovoltaic performance revealed that Al and In NPs produced broadband plasmonic light scattering and increased efficiency, far exceeding the results obtained using Ag NPs.

EQE response and photovoltaic performance of plasmonic silicon solar cells based on depositing with aluminum, indium, and silver nanoparticles

This study experimental demonstrated the plasmonic effects of Al-, In-, and Ag-nanoparticles (NPs) depositing on the silicon solar cells, respectively, according to external quantum efficiency and photovoltaic current-voltage. Efficiency enhancement of 22.68%, 20.88% and 17.10% for the cell with In-, Al- and Ag-NPs was obtained, compared to the reference cell.

Performance enhanced of MOS-structure silicon solar cell based on the integration of photovoltaic biasing source

High-performance MOS-structure silicon (Si) P/N-junction solar cell integrated with the photovoltaic-biasing source on the ceramic-substrate is demonstrated for the first time. The photovoltaic-biasing source was consisted of a series of small-area Si-solar-cells using die-bonding and wire-bonding integrated techniques and its output provides a photovoltaic voltage to bias the MOS-structure Si solar cell. The biasing voltage was changed from 0.55 V (one cell) to 2.75 V (five cells series connected). At photovoltaic biasing of 2.75 V, the short-circuit-current enhancement (ΔIsc) of 55.1% and conversion-efficiency enhancement (Δη) of 45.2% are obtained, compared to the MOS-structure Si solar cell with 0 V biasing.

Photovoltaic performance enhancement of plasmonics silicon solar cells using indium nanoparticles embedded in Al2O3/TiO2 layer structure

The photovoltaic performance enhancement of silicon solar cells depositing indium nanoparticles (In NPs) on TiO₂ layer and capping an Al₂O₃ layer was demonstrated. The impressive performance enhanced was attributed to the In NPs broadband light scattering based on Al₂O₃/TiO₂ antireflection. The optical reflectance, photovoltaic current-voltage, and external quantum efficiency were measured and compared with various thickness of TiO₂ layer. The efficiency enhancement of 54.5% (from 10.96% to 16.93%) was obtained when the cell with In NPs embedded in the Al₂O₃ (65-nm)/TiO₂ (20-nm) structure.

Demonstration of high efficiency 19.68% MOS-structure silicon solar cell based on 20-nm TiO2 space layer at 4V biasing

The photovoltaic performance enhanced of a MOS-structure silicon solar cell with transparent-ITO/oxide-film and basing voltage on the ITO electrode is experimentally demonstrated. High transmittance (> 80%) and conductivity (> 4.637×107 μs/cm) of ITO film is obtained using a thermal sputtering deposition. The antireflective characteristics of ITO/TiO2 and ITO/SiO2 are simulated and characterized. Photovoltaic current-voltage, external quantum efficiency, and performance as a function of the biasing voltage are measured. The conversion efficiency increasing from 14.06% to 19.68% is obtained for the proposed MOS cell at 4 V biasing, compared to at 0 V one.

Improved the current matching of the middle-cell current-limited triple-junction GaAs/Ge solar cells after epitaxial grown using matrix profile TiO 2 layer and indium nanoparticles plasmonics

The current matching of the middle-cell current-limited triple-junction GaAs/Ge solar-cells after-epitaxial-growth was improved using the matrix-profile TiO2 layer and indium-nanoparticles plasmonics. The optical reflectance, short-circuit current, conversion efficiency and external quantum efficiency are used to characterize the effects of the matrix-profile TiO2 layer and indium-nanoparticles plasmonics on the performances of solar cells. The cell with indium-nanoparticles deposited on the combined layers of a 10-nm-thick TiO2 and a 30-nm-thick TiO2 of 60% coverage shown the improving of current matching in middle-cell that increasing in conversion efficiency by 8.36% and short-circuit current of 12.91% are obtained, compared to the bare solar cells.

Fabrication of plasmonics Si solar cells based on indium nanoparticles and TiO 2 space layer

We demonstrate experimentally the photovoltaic performance enhancement of the plasmonics silicon solar cell based on nano-sized indium-particles and different thickness of TiO2 space layer. The reflectance, photo-current and external quantum efficiency are measured and compared at each stages of device processing. The conversion efficiencies enhancing of 17.78% and of 47.85% are obtained as the solar cell with indium nanoparticles on a 10-nm and a 59.5-nm thick TiO2 space layer, respectively, compared to the solar cell without coated a TiO2 layer. Furthermore, the plasmonics conversion efficiencies depend on the thickness of space layer are also demonstrated that the increasing by 15.46% and 6.08% for the solar cells with 10-nm and a 59.5-nm thick TiO2 space layer, respectively.