e jk (C -1 ) kj . Typically, d 33 is the important piezoelectric constant for applications such as resonators or actuators. We find that FE doped h-BN exhibits a surprisingly large value d 33 (from -5.154 to 24.214 pC/N), Table . This is about 5 times larger than that of commercially used w -AlN (d 33 ~5 pC/N), while w -GaN has a low d 33 of ~3 pC/N . Unlike w -AlN, the computed d 33 in doped h-BN shows a negative sign because of the negative e 33 , suggesting that these doped structures would shrink (expend) in response to an electric field along positive (negative) z-direction. Our doped h-BN structures are van der Waals layered materials, hence posses quite low C 33 (see Table ). This facilitates the large d 33 , which is comparable with that of Sc doped w -AlN, for which d 33 ~25 pC/N at around 27% Sc doping and also that of FE polymer PVDF-TrFE, for which d 33 = -25 pC/N . Therefore, these doped h-BN can be good material for piezoelectric applications in energy harvesting or as actuators.