The characteristics of the graded-gap AlGaAs-GaAs-InGaAs Gunn diodes

The usage of graded-gap semiconductors in the Gunn diodes results in increasing the output power and efficiency of the electromagnetic waves generation. However, the ternary compound InGaAs does not create the optimal distribution profile of binary semiconductor components. This disadvantage can be eliminated in AlGaInAs compound. The paper presents the following results: firstly, the numerical experiments on the generation of oscillations in wide frequency range by means of Gunn diodes based on graded-gap AlGaInAs has been carried out, secondly, the parameters has been optimized and, thirdly, diodes output characteristics has been obtained. The study showed that AlGaInAs graded-gap Gunn diodes outperform the InGaAs and AlGaAs diodes of same type on generation efficiency, output power and cutoff frequency. The results of the study extend the knowledge of the physical processes of carrier transport in complex semiconductor structures and can be useful for the development of new high-speed devices based on graded-gap semiconductor compounds.