We grew modulated BeZnO layers by hybrid plasma-assisted molecular-beam epitaxy/electron-beam deposition. A wide band-gap investigation of the modulated Be (x) Zn1-x O by means of photocurrent (PC) spectroscopy was conducted. The band-gap energy was directly acquired from the wavelength of the PC peak, caused by the band-to-band transition. By increasing x, which was the rate of the Be elements, the optical band-gap energy was empirically fitted by E (BeZnO)(x) = 6.32(x-1)x + 7.305x + 3.295. We expect that this finding can open new possibilities for wide band-gap engineering of BeZnO layers, which can be utilized as barrier layers in active layers consisting of ZnO/BeZnO quantum well structures and solar-blind ultraviolet photodetectors.