Wide bandgap devices are formed on a diamond substrate, such as for light emitting diodes as a replacement for incandescent light bulbs and fluorescent light bulbs. In one embodiment, diodes (or other devices) are formed on diamond in at least two methods. A first method comprises growing a wide bandgap material on diamond and building devices on that grown layer. The second method involves bonding a wide bandgap layer (device or film) onto diamond and building the device onto the bonded layer. These devices may provide significantly higher efficiency than incandescent or fluorescent lights, and provide significantly higher light or energy density than other technologies. Similar methods and structures result in other wide bandgap semiconductor devices.