A model is proposed that makes it possible to analytically analyze the speed performance of a waveguide p-i-n photodiode with a light-absorbing region representing a multilayered array of quantum dots separated by undoped spacers. It is shown that there is an optimal number of layers of quantum dots, as well as an optimal thickness of the spacers, which provide the widest bandwidth. The possibility of achieving a frequency range (at the level of -3 dB) above 20 GHz for waveguide photodiodes based on InGaAs/GaAs quantum well-dots is shown.

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High-speed photodetectors (PDs) based on InGaAs/GaAs quantum well-dots (QWDs) nanostructures are investigated. The -3 dB bandwidth of 8.2 GHz at 905 nm has been demonstrated. It is shown that internal processes in QWDs make it possible to create a PD with a bandwidth of up to 12.5 GHz, and the processes of thermalization of carriers from QWD layers do not limit the speed at reverse biases of more than 5 V.