Several InAsP/InP p-i-n Multi-Quantum Well (MQW) solar cells, only differing by their MQW region composition and geometry, were investigated. For each sample, the Arrhenius plot of the temperature related variation of the photoluminescence intensity was used to deduce the radiative recombination activation energy. The electron and holes confinement energy levels in the quantum wells and the associated effective potential barriers seen by each carrier were theoretically calculated. Carrier escape times were also estimated for each carrier. The fastest escaping carrier is found to display an effective potential energy barrier equal to the experimentally determined photoluminescence activation energy. This not only shows that the temperature related radiative recombination extinction process is driven by the carrier escape mechanism but also that the carriers escape process is sequential. Moreover, a discrepancy in device performance is directly correlated to the nature of the fastest escaping carrier. © 2008 Materials Research Society.