2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC), 2018
This paper reports on the investigation of Al<inf>x</inf>Ga<inf>1-x</inf>... more This paper reports on the investigation of Al<inf>x</inf>Ga<inf>1-x</inf>As<inf>y</inf>Sb<inf>1-y</inf> alloys lattice-matched to GaSb for multi-junction solar cell applications. Optical and electrical characterizations of Al<inf>x</inf>Ga<inf>1-x</inf>As<inf>y</inf>Sb<inf>1-y</inf> alloys are carried out to provide accurate material parameters for simulations. Simulations are then performed with these experimental data to propose an optimized and promising structure for Al<inf>x</inf>Ga<inf>1-x</inf>As<inf>y</inf>Sb<inf>1-y</inf> subcells.
In the crystalline silicon solar cell manufacturing wet etching process are widely used with a la... more In the crystalline silicon solar cell manufacturing wet etching process are widely used with a large usage of acid and DI water and with a limited capability of reflectivity reduction. In this work, we replace wet etching by plasma dry etching on 4 main processes. A new dry etch of saw damage coupled with front dry texturing and rear dry polishing provides the possibility to replace wet bench by new dry etching equipment. Batch processing drastically reduces the cost per wafer and increases the through put. Marathon test on 2000 multicrystalline wafers show a 0.2% absolute increase of efficiency compare to wet acidic etching. Compatibility with diamond wire sawn wafers is evaluated and at module level single cell mini module demonstrated no loss of performance on dry textured cells. In the last part, a dry plasma emitter rear emitter etch is developed. A fine adjustment of process parameters provides a gain in isolation and in Jsc corresponding to a 0.08% absolute efficiency gain.
In this work, we report on the diffusion process development of homogenous high ohmic phosphorous... more In this work, we report on the diffusion process development of homogenous high ohmic phosphorous emitters (50-170 Ω/sq). The use of reduced pressure diffusion LydopTM system has been evaluated in the range of 200 mbar to 400 mbar. We show the path for a significant breakthrough to achieve very uniform (<5%) high ohmic emitters while maintaining industrial throughputs, cost and yield. In the frame of advanced cells structures, several ohmic emitters (>100 Ω/sq) have been coupled with an external thermal SiO2 passivation keeping a well-controlled process uniformity by using the LytoxTM reduced pressure technology.
The heterogeneous integration of a GaSb subcell into a 4-terminal cell is currently experiencing ... more The heterogeneous integration of a GaSb subcell into a 4-terminal cell is currently experiencing a regain of interest for high concentrator multijunction photovoltaics. In this context, the assessment of the lateral charge carrier transport in a GaSb cell under concentrated light is fundamental. The characterization and modeling of a GaSb single-junction solar cell under concentration are presented here. The originality of this article resides in the fine analysis of experimental data using an in-house pseudo-3-D model where the intrinsic diode is modeled with a temperature-dependent 1-D physical model. The limiting factors responsible for the performance drop under concentrated light are discussed. It is also demonstrated that an efficiency of 12.5% can be reached under 64 suns with realistic technological improvements.
Physica E-Low-Dimensional Systems & Nanostructures, 2008
ABSTRACT Dilute-nitride InAsN/GaSb/InAsN “W” laser structure is theoretically investigated and co... more ABSTRACT Dilute-nitride InAsN/GaSb/InAsN “W” laser structure is theoretically investigated and compared with similar nitride-free InAs/GaSb/InAs “W” structure. The two laser diodes, to be grown on (0 0 1) InAs substrate, are designed to operate at 3.3 μm at room temperature. Their performances are evaluated in terms of modal gain and radiative efficiency characteristics deduced from optical gain calculation. We find that the inclusion of nitrogen in the laser active region improves optical gain performances leading to peak gain values of the order of 1000 cm−1 for typical injected carrier concentration of 1.5×1018 cm−3. Modal gain value equal to 70 cm−1 can be achieved and radiative current density inferior to 100 A/cm2 is predicted. These results demonstrate that the dilute-nitride InAsN/GaSb/InAsN laser structure is very attractive for room temperature operation in the midwave infrared domain.
2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC & 34th EU PVSEC), 2018
This paper reports on the investigation of Al<inf>x</inf>Ga<inf>1-x</inf>... more This paper reports on the investigation of Al<inf>x</inf>Ga<inf>1-x</inf>As<inf>y</inf>Sb<inf>1-y</inf> alloys lattice-matched to GaSb for multi-junction solar cell applications. Optical and electrical characterizations of Al<inf>x</inf>Ga<inf>1-x</inf>As<inf>y</inf>Sb<inf>1-y</inf> alloys are carried out to provide accurate material parameters for simulations. Simulations are then performed with these experimental data to propose an optimized and promising structure for Al<inf>x</inf>Ga<inf>1-x</inf>As<inf>y</inf>Sb<inf>1-y</inf> subcells.
In the crystalline silicon solar cell manufacturing wet etching process are widely used with a la... more In the crystalline silicon solar cell manufacturing wet etching process are widely used with a large usage of acid and DI water and with a limited capability of reflectivity reduction. In this work, we replace wet etching by plasma dry etching on 4 main processes. A new dry etch of saw damage coupled with front dry texturing and rear dry polishing provides the possibility to replace wet bench by new dry etching equipment. Batch processing drastically reduces the cost per wafer and increases the through put. Marathon test on 2000 multicrystalline wafers show a 0.2% absolute increase of efficiency compare to wet acidic etching. Compatibility with diamond wire sawn wafers is evaluated and at module level single cell mini module demonstrated no loss of performance on dry textured cells. In the last part, a dry plasma emitter rear emitter etch is developed. A fine adjustment of process parameters provides a gain in isolation and in Jsc corresponding to a 0.08% absolute efficiency gain.
In this work, we report on the diffusion process development of homogenous high ohmic phosphorous... more In this work, we report on the diffusion process development of homogenous high ohmic phosphorous emitters (50-170 Ω/sq). The use of reduced pressure diffusion LydopTM system has been evaluated in the range of 200 mbar to 400 mbar. We show the path for a significant breakthrough to achieve very uniform (<5%) high ohmic emitters while maintaining industrial throughputs, cost and yield. In the frame of advanced cells structures, several ohmic emitters (>100 Ω/sq) have been coupled with an external thermal SiO2 passivation keeping a well-controlled process uniformity by using the LytoxTM reduced pressure technology.
The heterogeneous integration of a GaSb subcell into a 4-terminal cell is currently experiencing ... more The heterogeneous integration of a GaSb subcell into a 4-terminal cell is currently experiencing a regain of interest for high concentrator multijunction photovoltaics. In this context, the assessment of the lateral charge carrier transport in a GaSb cell under concentrated light is fundamental. The characterization and modeling of a GaSb single-junction solar cell under concentration are presented here. The originality of this article resides in the fine analysis of experimental data using an in-house pseudo-3-D model where the intrinsic diode is modeled with a temperature-dependent 1-D physical model. The limiting factors responsible for the performance drop under concentrated light are discussed. It is also demonstrated that an efficiency of 12.5% can be reached under 64 suns with realistic technological improvements.
Physica E-Low-Dimensional Systems & Nanostructures, 2008
ABSTRACT Dilute-nitride InAsN/GaSb/InAsN “W” laser structure is theoretically investigated and co... more ABSTRACT Dilute-nitride InAsN/GaSb/InAsN “W” laser structure is theoretically investigated and compared with similar nitride-free InAs/GaSb/InAs “W” structure. The two laser diodes, to be grown on (0 0 1) InAs substrate, are designed to operate at 3.3 μm at room temperature. Their performances are evaluated in terms of modal gain and radiative efficiency characteristics deduced from optical gain calculation. We find that the inclusion of nitrogen in the laser active region improves optical gain performances leading to peak gain values of the order of 1000 cm−1 for typical injected carrier concentration of 1.5×1018 cm−3. Modal gain value equal to 70 cm−1 can be achieved and radiative current density inferior to 100 A/cm2 is predicted. These results demonstrate that the dilute-nitride InAsN/GaSb/InAsN laser structure is very attractive for room temperature operation in the midwave infrared domain.
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Papers by Yvan Cuminal