Electron and Proton Radiation Effects on Band Structure and Carrier Dynamics in MBE and MOCVD Grown III-V Test Structures

As part of a study on radiation effects in optoelectronic materials, we exposed a series of AIGaAs/GaAs double heterostructures grown by molecular beam epitaxy and metalorganic chemical vapor deposition to electron and proton radiation. The active regions of the test articles were either p-, n-, or unintentionally doped. Steady state and time resolved photoluminescence spectroscopy were used to characterize radiation induced changes to the band structure and carrier dynamics. The effects of electron radiation on low temperature photoluminescence spectra and room temperature carrier dynamics varied with dopant type and density. Steady-state photoluminescence reveals distinct proton exposure effects for p-type materials grown by molecular beam epitaxy compared to n-type structures. Both the steady state and time resolved results suggest that n-type materials are more radiation hard to the effects of 1 MeV electrons than p-type materials.