ABSTRACTHigh performance and cost effective multi-junction III-V solar cells are attractive for satellite applications. High performance multi-junction solar cells are based on a triple-junction design that employs an InGaP top-junction, a GaAs middle-junction, and a bottom-junction consisting of a 1.0 – 1.25 eV-material. The most attractive 1.0 – 1.25 eV-material is the lattice-matched dilute nitride such as InGaAsN(Sb). A record efficiency of 43.5% was achieved from multi-junction solar cells including dilute nitride materials [1]. In addition, cost effective manufacturing of III-V triple-junction solar cells can be achieved by employing full-wafer epitaxial lift-off (ELO) technology, which enables multiple substrate re-usages. We employed time-resolved photoluminescence (TR-PL) techniques to study carrier dynamics in both pre- and post-ELO processed GaAs double heterostructures (DHs) as well as in MOVPE-grown bulk dilute nitride layers lattice matched to GaAs substrates.