High Current Density Diamond Photoconductive Semiconductor Switches with a Buried, Metallic Conductive Channel

Laterally configured diamond photoconductive semiconductor switches (PCSS) with a buried, metallic p+ current channel are reported. Above bandgap (λ ≤ 226nm) optical triggering enables responsivity of over 130 mA/W. The use of low-impurity semi-insulating diamond as an active absorption layer enables fast rise and fall times (2 ns) and on/off ratios greater than 1011. The PCSS excited with a laser energy of 20 nJ per pulse passes a high current density (44 A/cm) under a DC bias of 60 V, thanks to the buried metallic p+ current channel. The reported devices promise high current carrying capacity without the need for filamenting while leveraging the excellent optical, electronic, and thermal properties of diamond.