UV diamond power switches

Optically triggered surface channel MESFETs were fabricated on commercial polycrystalline diamond to be tested as fast UV activated switches. Devices with an opaque-gate and asymmetric structure were designed in order to improve charges photogeneration within gate-drain region. The sensitivity to UV light was demonstrated by using both modulated over gap radiation and laser pulses at 193 nm, well over the diamond band gap. Linearity with the power light was demonstrated as well as the parabolic dependence of the photogenerated current on the gate-source voltage when the transistor is in saturation. The transient response to 193 nm laser pulses in the nanosecond regime shows as the photogeneration process and charges collection to the drain contact are completed in a time scale of few nanoseconds.