A method of manufacturing a photocathode includes forming a seed layer with a single crystal structure on a faceplate; forming a window layer over the seed layer; and forming an active layer over the window layer. The method can also include the step of cleaning the faceplate before the seed layer is formed. The steps of cleaning the faceplate, forming the seed layer, forming the window layer and forming the active layer are performed in an organometallic chemical vapor deposition reactor system. The seed layer is formed by depositing a buffer layer on the faceplate and annealing the buffer layer to form the seed layer having. The atmosphere during the annealing of the buffer layer includes hydrogen, arsine, trimethylaluminum, and trimethylgallium. A photocathode formed from the method is also disclosed.