Influence of active-layer width on the performance of homojunction and single-heterojunction GaAs light-emitting diodes

For epitaxial GaAs homojunction and single-heterojunction (s.h.) l.e.d.s, light power output and risetime as a function of active-layer width were investigated. Narrow-base homojunction diodes can be markedly faster than s.h. diodes, the rise time of which is limited by the electron lifetime. However, for equal width of the active layer and equal injection level, the light power output of s.h. diodes is superior, compared with that of homojunction diodes.