Avalanche multiplication and breakdown in Ga0.52In0.48P diodes

The electron and hole photomultiplication characteristics M, and M _h have been measured in a series of Ga_0.52In_0.4xP devices with high field regions ranging from 2.0 μm down to the depletion width of a heavily doped p-n junction. The hole ionization coefficient β is found to be slightly higher than the electron ionization coefficient α at low fields but at high fields they approach one another. α and β are found to be significantly lower than in GaAs across the entire range of electric fields studied, and the breakdown voltage of Ga_0.52 In_0.48P is approximately 1.9 times higher than for similar GaAs structures. Contrary to the behavior observed in GaAs, the multiplication characteristics in all except the thinnest structures appear to be relatively unaffected by the dead space, the minimum distance required to gain sufficient energy to initiate impact ionization. In these very thin structures, a local description of multiplication cannot account for the ionization behavior accurately, and therefore, a Monte Carlo (MC) model has been used to reproduce the measured multiplication characteristics and extract the ionization coefficients