  Silicon photonics is destined to revolutionize technological areas, such as
short-distance data transfer and sensing applications by combining the benefits
of integrated optics with the assertiveness of silicon-based microelectronics.
However, the lack of practical and low-cost silicon-based monolithic light
sources such as light-emitting diodes and, in particular, lasers is the main
bottleneck for silicon photonics to become the key technology of the 21st
century. After briefly reviewing the state of the art regarding silicon-based
light-emitters, we discuss the challenges and benefits of a highly flexible
approach: The epitaxial incorporation of group-IV nanostructures into
crystalline silicon. We argue that a paradigm change for group-IV quantum dots
(QDs) can be achieved by the intentional incorporation of extended point
defects inside the QDs upon low energy ion implantation. The superior
light-emission properties from such defect-enhanced quantum dots (DEQDs), our
present understanding of their structural formation and light-emission
mechanisms will be discussed. We will show that useful electrically-driven
devices, such as light-emitting diodes (LEDs) can be fabricated employing
optically active DEQD-material. These LEDs exhibit exceptional
temperature-stability of their light emission properties even up to 100{\deg}C,
unprecedented for purely group-IV-based optoelectronic devices. Thereafter, we
will assess the superior temperature stability of the structural properties of
DEQDs upon thermal annealing, the scalability of the light-emission with the
DEQD density and passivation schemes to further improve the optical properties.
The chapter ends with a discussion of future research directions that will
spark the development of this exciting field even further.
