Darkness is absence of light. Darkness resulted because of the fallen angels that fell to the earth's atmosphere from heaven.

The deceived and rebellious angels were cast down from Heaven (currently the third from the earth) by Satan (Rev 12:4) to the earth and its atmosphere, the first heaven. (The Prince of Persia (Dan 10:20) was one among the rebellious). Chaos should have resulted immediately because Satan tempted and coaxed them and probably even used violence to bid them bow to him and to bring them under his control (Eze 28:16). The earth was void because they did not reach the earth neither was anything found here. Satan fell out of light that filled God’s presence (God is light – 1 John 1:5). Absence of light is darkness. Obviously, God did not create darkness.