The dark-energy-dominated era began after the matter-dominated era, i.e. when the Universe was about 5 billion years old.

Thus, in the early part of the matter-dominated era, stable protons and neutrons formed, which then associated into atomic nuclei.

Radiation-dominated era, matter-dominated era and Dark-energy-dominated era, another way that the universe's chronology is categorized.

The dark-energy-dominated era refers to the last of the three phases of the known universe, the other two being the matter-dominated era and the radiation-dominated era.

The matter-dominated era was the epoch in the evolution of the Universe that began when the radiation-dominated era ended, when the Universe was about 47,000 years old.

In the matter-dominated era, the energy density of matter exceeds the energy density of radiation in the universe (and it should exceed the vacuum energy density i.e. dark energy, too).

Although it was often said that we still live in the matter-dominated era, it is more correct to say that when the Universe was about 9.8 billion years old, this era ended and was replaced by the dark-energy-dominated era.