Details

Autor(en) / Beteiligte

• Schulte, Kevin L.
• Metaferia, Wondwosen
• Simon, John
• Ptak, Aaron J.

Titel

Uniformity of GaAs solar cells grown in a kinetically-limited regime by dynamic hydride vapor phase epitaxy

Ist Teil von

• Solar energy materials and solar cells, 2019-08, Vol.197 (C), p.84-92

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We demonstrate solar cell devices grown on 50 mm diameter GaAs substrates by dynamic hydride vapor phase epitaxy (D-HVPE). In contrast to our prior D-HVPE devices, grown at 650 °C in a transport-limited regime, these devices were grown at 700 °C in a kinetically-limited growth regime in which the growth rate uniformity is controlled by thermally-activated surface reactions. These devices exhibit open-circuit voltages up to 1.07 V, nearly identical performance to the devices grown at lower temperature in a different growth regime. We evaluate the uniformity of device performance and find only a 1% variation in absolute, device efficiency across the majority of the wafer in devices without anti-reflection coating. We analyze the GaAs and GaInP thickness uniformity and GaInP compositional uniformity, using high-tresolution x-ray diffraction mapping, and find that any non-uniformity in device efficiency is not related to variations in these structural parameters. We combine three-dimensional computational fluid dynamics modeling of our reactor with a kinetic model for GaAs growth, and use the combined model to predict spatial GaAs growth rate over a 50 mm wafer area. We compare these predictions with experimental data from our D-HVPE reactor and find excellent agreement. We use the model to the gain insight into the specific mechanisms that control GaAs spatial uniformity in the kinetically-limitedgrowth regime. These results suggest a large parameter window for the growth of high-performance optoelectronic devices by D-HVPE, possibly with large area uniformity. •Analyzed uniformity of GaAs solar cells grown on 50 mm wafer.•Devices exhibited excellent performance, with VOC up to 1.07 V.•Devices exhibited excellent thickness and compositional uniformity.•Developed CFD + kinetic model to predict spatial growth rate with good accuracy.