Integration of rare earth ions doped Si based down converter layers in an industrial Si solar cell

International audienceGoal : Improve the efficiency of Si solar cells by down converter layer Decrease the thermalization losses due to the spectral mismatch between the solar irradiance and the Si absorption Use the optical properties of rare earth ions embedded in a Si-based matrix to do Down-conversion (DC) Integration in industrial Si solar cell Fabrication parameters: Depositions parameters: Deposition Temperature , T dp (°C) Plasma Pressure, P tot (sccm) Gaz : Argon and nitrogen Nitrogen rate, rN 2 RF Power density on target, P target (W/cm²) Depositing time, t dp (s) Annealing with rapid or slow ramp of T under specific gas (N 2 , Forming…) PHC France-Taiwan ORCHID. Targets Rotation Heating lamp Radio-frequency Power (PRF) SiO 2 Water-cooled Water-cooled Water-cooled Water-cooled Water-cooled Water-cooled Substrate Gas Argon Argon Plasma Magnets Target Shutter M.PII.11 Conclusion Fabrication of Tb/Yb-doped SiN x homogenous and multilayer films->DC optimized films Modeling of the DC interaction exchange for both kind of films-> Aggregation of rare earth ions is prevented in multilayer Homogenous and multilayer DC layers integrated in Si solar cell-> Homogenous DC layer lead to relative Si solar cell efficiency increase of 1.34% Introduction confocal magnetron sputtering Si based doped with rare earth ions luminescent layer: SiNx-Tb 3+ [PHOTOLUMINESCENCE] Control of refractive index by tuning the sputtering parameters : SiN x [ELLIPSOMETRY] Brewster LO 1120 cm-1 TO 840 cm-1 Amorphous and homogenous films: SiN x [HRTEM] Control of the stoichiometry by tuning the sputtering parameters: SiN x [FTIR] Structural and physical characterization Monte Carlo Modeling K CET distance dependent and therefore function of concentration [Tb 3+ ] and [Yb 3+ ] and their distribution Two kinds of Tb 3+-Yb 3+ co-doped thin films fabricated homogenous and multilayer Multilayer prevent aggregation quenching and allow therefore higher doping rate Relative increase by 1.34% in the solar cell conversion efficiency E-Ton Solar (Taiwan) Pseudo I-V curves for three c-Si solar cells with SiN x , SiN x :Tb 3+ and SiN x :Tb 3+-Yb 3+ layers, respectively. Reflectance of three layers deposited on textured emitter