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Experimental investigations have been carried out into the annealing and transient effects in the characteristics of some commercially available GaAs-based Schottky and light emitting diodes (LEDs) along the line of the two roots model. The ideality factor m ( ∼ =1.3) in the Schottky diode is constant over the range of annealing temperatures (T a ) and over different waiting times (t). TSC measurements indicate the presence of five sets of traps at T a = 200 • C and T a = 250 • C. A change in T a leads to a change in the trap energy-levels.Furthermore appearance and disappearance of a hysteresis loop take place with annealing, giving rise to a change in the power (P ) involved within the loop.

Generation-recombination processes have been studied with the use of a phenomenological approach. The approach is in principle based on the combined mechanisms involved in the dominant deep-level traps and in radiative and nonradiative processes in these devices. It is possible with the use of the approach to predict different types of carrier transition phenomena under zero- and nonzero-bias conditions. Carrier phase diagrams have been produced which can depict, in classified form, all possible transitions as a function of the coefficients involved in the phenomena. Attempts have also been made to deal with the generation-recombination processes associated with the midgap single-level impurities, in line with Shockley–Hall–Read theory. The approach leads to the development of a two-root model which demonstrates the existence or nonexistence of hysteresis in the I-V characteristics of devices. Detailed mathematical results and physical modeling have been presented. Graphical representation and experimental evidence of the model have also been produced.