Enhancement mode, field effect transistors wherein at least a portion of the transistor structure may be substantially transparent. One variant of the transistor includes a channel layer comprising a substantially insulating, substantially transparent, material selected from ZnO, SnO2, or In2O3. A gate insulator layer comprising a substantially transparent material is located adjacent to the channel layer so as to define a channel layer/gate insulator layer interface. A second variant of the transistor includes a channel layer comprising a substantially transparent material selected from substantially insulating ZnO, SnO2 or In2O3, the substantially insulating ZnO, SnO2, or In2O3 being produced by annealing. Devices that include the transistors and methods for making the transistors are also disclosed.