The PHENIX experiment at RHIC measured single electron spectra in p + p, d + Au and Au + Au collisions at \(\sqrt{s_{NN}} = 200\) GeV, and in Au + Au collisions at \(\sqrt{s_{NN}} = 62.4\) GeV. In these spectra, electrons from semi-leptonic decays of charmed particles are the dominant contribution after subtraction of all 'photonic' sources (photon conversions, Dalitz decays, decays of light vector mesons). The p + p open charm production cross-section is found to be in good agreement with pQCD NLO calculations. The shape of the distributions obtained for p + p interactions is compared with those observed for nucleus-nucleus collisions. From p + p to d + Au and Au + Au interactions, open charm production is found to scale with the number of binary collisions \(N_{\rm coll}\). Au + Au data at \(\sqrt{s_{NN}} = 62.4\) GeV is compatible with the ISR p + p results scaled by \(N_{\rm coll}\). The elliptic flow parameter v2 of heavy flavor electrons has also been measured, and is found to be non-zero in the intermediate pT range.