DC Solar cable are single core copper cables each for +ve and -ve, They are insulated and sheathed with cross linkable LSZH which has UV as well as ozone protection properties (generally conforming to BS EN 50618:2014)
In general, there are three types of cables used in a PV system: DC solar cables, solar DC main cables, and solar AC connection cables. DC solar cables can either be module or string cables. Typically, these are single core copper cables with insulation and sheathes