@inproceedings{207eb9221da44b419dc77b128d495a94,
title = "Carrier dynamics in bulk 1eV InGaAsNSb materials and epitaxial lift off GaAs-InAlGaP layers grown by MOVPE for multi-junction solar cells",
abstract = "III-V multi-junction solar cells are based on a triple-junction design that consists of an InGaP top junction, a GaAs middle junction, and a bottom junction that employs either a 1eV material grown on the GaAs substrate or InGaAs grown on the Ge substrate. The most promising 1 eV material that is currently under extensive investigation is bulk dilute nitride such as InGaAsN(Sb) lattice matched to GaAs substrates. Both approaches utilizing dilute nitrides and lattice-mismatched InGaAs layers have a potential to achieve high performance triple-junction solar cells. In addition, it will be beneficial for both commercial and space applications if III-V triple-junction solar cells can significantly reduce weight and can be manufactured cost effectively while maintaining high efficiency. The most attractive approach to achieve these goals is to employ full-wafer epitaxial lift off (ELO) technology, which can eliminate the substrate weight and also enable multiple substrate re-usages. For the present study, we employed time-resolved photoluminescence (TR-PL) techniques to study carrier dynamics in MOVPE-grown bulk dilute nitride layers lattice matched to GaAs substrates, where carrier lifetime measurements are crucial in optimizing MOVPE materials growth. We studied carrier dynamics in InGaAsN(Sb) layers with different amounts of N incorporated. Carrier lifetimes were also measured from InGaAsN(Sb) layers at different stages of post-growth thermal annealing steps. Post-growth annealing yielded significant improvements in carrier lifetimes of InGaAsNSb double hetero-structure (DH) samples compared to InGaAsN DH samples possibly due to the surfactant effect of Sb. In addition, we studied carrier dynamics in MOVPE-grown GaAs-InAl(Ga)P layers grown on GaAs substrates. The structures were grown on top of a thin AlAs release layer, which allowed epitaxial layers grown on top of the AlAs layer to be removed from the substrate. The GaAs layers had various doping densities and thicknesses. We present our TR-PL results from both pre- and post-ELO processed GaAs-InAl(Ga)P samples.",
keywords = "Dilute nitride, MOVPE, TR-PL, carrier dynamics, epitaxial lift off, multi-junction solar cell",
author = "Yongkun Sin and Stephen LaLumondiere and William Lotshaw and Moss, {Steven C.} and Kim, {Tae Wan} and Kamran Forghani and Mawst, {Luke J.} and Kuech, {Thomas F.} and Rao Tatavarti and Andree Wibowo and Noren Pan",
year = "2013",
doi = "10.1117/12.2001528",
language = "English",
isbn = "9780819493897",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
booktitle = "Physics, Simulation, and Photonic Engineering of Photovoltaic Devices II",
note = "2nd Symposium on Physics, Simulation, and Photonic Engineering of Photovoltaic Devices ; Conference date: 03-02-2013 Through 07-02-2013",
}