Terminology related to panpsychism
William Seager’s chapter, “Panpsychism”, is a useful introduction to the terminology of panpsychism and it contains references.
Seager refers to “mentality” rather than “mind”, but the key idea of panpsychism is that mentality is (1) ontologically “fundamental”, meaning it cannot be reduced to something more basic, and (2) it is “ubiquitous”--everywhere.
This is not Descartes’ “substance dualism”. Cartesian mentality is fundamental but it is not ubiquitous. Mentality gets attached dualistically to what is not mental and, I suspect, there could be forms of mentality that are not attached to any unconscious matter.
It is also not physicalism (or materialism). Physicalism is almost the opposite of panpsychism. The physicalist believes that unconscious matter is both fundamental and ubiquitous and mentality “emerges” from the non-mental in mysterious ways.
The opposite of physicalism would be a form of idealism where mentality is both fundamental and ubiquitous and whatever is unconscious emerges from mentality. That is, the unconscious can be reduced everywhere to the mental. Most panpsychists do not go this far. They believe there is some unconscious fundamental reality, but this idealism would be a form of panpsychism.