Doping is a critical in piezoelectric base materials used as sensors or energy harvesters. It has a significant effect in determining the output parameters of an energy harvester. This paper studies the effect and impact on piezoelectric properties when materials are co doped and singly doped by considering some common dopants found in the literature. From the study, the elastic constant and c/a ratio are found to be decreasing and all other lattice parameters such as piezoelectric stress coefficient, electromechanical coupling constant, Born effective charge etc. are increasing, although some discrepancies are there. Scandium, magnesium, Lithium and its co-dopants are mainly considered for the study. Another factor that should be considered is doping concentration. Excessive doping with scandium (Sc) has been demonstrated to reduce the coercive field (Ec), enabling ferroelectric switching in AlScN thin films. The critical factor for achieving ferroelectric switching lies in sufficiently lowering the energy barrier between the two polarization states made of the wurtzite structure. This can be accomplished either by increasing the proportion of the non-Group-III metal or through strain engineering.