Increase in the photocurrent in layers of Ge/Si quantum dots by modes of a two-dimensional photonic crystal

It has been found that the introduction of layers of Ge/Si quantum dots in a two-dimensional photonic crystal leads to a strong (up to a factor of 5) increase in the photocurrent in the near infrared range. The photonic crystal is a regular triangular array of holes in a Si/Ge/Si heterostructure grown on a silicon-on-insulator substrate. The results have been explained by the excitation of planar modes of the photonic crystal, which propagate along the Ge/Si layers and effectively interact with interband transitions in quantum dots, by the incident light wave.