We report on the basis of density functional theory, the field emission properties of pristine and doped aluminum nanocone (Al-NC). We substituted the apex of the Al-NC with group IV and group V elements, namely arsenic (As), germanium (Ge) and phosphorous (P) atoms and had carried out studies on these nanocone structures. The density of states (DOS) spectrum gives a clear perception of the charge distribution over the Al-NC surface on doping. Furthermore, the Richardson-Dushman formula has been used to correlate the work function Φ and the charge density. We have observed that doping at the apex of Al-NC leads to the variation in work function Φ. The results show that the field emission properties of Al-NC can be improved with the substitution of As, Ge, and P at the apex of the structure. Our findings suggest that doping of the Al-NC with Ge, As and P leads to the improved field emission properties, which can be used for nanoelectronics and vacuum electronics.