Radiation Damage in Semiconductor Light Emitting Devices

"Irradiation of particles such as protons and neutrons does various damages to light emitting devices. In semiconductor lasers, the most important effect is an increase in threshold current. This effect is characterized as the threshold current damage factor K_I. Dependence of K_I on incident particle energy and materials of active regions is discussed using non-ionizing energy loss (NIEL) and displacement energy. Furthermore, K_I is discussed taking account of a decrease in carrier lifetime due to non-radiative centers (defects) introduced by irradiation of particles.