Good Morning, The equations under investigation: Electrons: J = enμE + eD(dn/dx) Holes: J = epμE - eD(dp/dx) n or p = concentration of electrons or holes respectively D = diffusion constant μ = mobility The question in mind is as follows: If holes are traveling in the direction on conventional current, then shouldn't the drift velocity for holes be fully negative, i.e. -epμE - eD(dp/dx)? I understand by definition that, μ = mobility, is the absolute value of drift velocity (speed) over the electric field hence the direction is lost in the process (or is the same for both a hole and an electron). Therefore, shouldn't the expression for holes written above also technically factor in a negative sign corresponding to the hole drift 'velocity' part of the equation? Please dispel my confusion lest more holes puncture brain.