Pure blue light emission has been obtained from ZnSep‐njunctions. ZnSe crystals are grown by the temperature difference solution growth method under controlled vapor pressure. Ap‐type ZnSe crystal can be grown from Se solution by doping with a group I element under controlled Zn pressure. The properties ofp‐type crystals have been measured by the van der Pauw method. Ap‐njunction has been made by the formation of then‐type layer by Ga diffusion into thep‐type crystal. The fundamental properties of thep‐njunctions are as follows: the value ofnin the I‐V characteristics ranges from 1.4 to 1.8 and the diffusion potential is between 2.5 and 2.7 eV. The emission spectrum from thep‐njunction depends on the vapor pressure during growth and blue light emission is obtained with optimum pressure. The wavelength of the main emission peak is 460 nm at 77 °K and 480 nm at 300 °K. The brightness is 2 mcd at 2 mA.