Transient lateral photovoltaic effect in patterned metal-oxide-semiconductor films

The time dependent transient lateral photovoltaic effect has been studied with µs time resolution and with chopping frequencies in the kHz range, in lithographically patterned 21 nm thick, 5, 10 and 20 µm wide and 1500 µm long Co lines grown over naturally passivated p-type Si (100). We have observed a nearly linear dependence of the transitorial response with the laser spot position. A transitorial response with a sign change in the laser-off stage has been corroborated by numerical simulations. A qualitative explanation suggests a modification of the drift-diffusion model by including the influence of a local inductance. Our findings indicate that the microstructuring of position sensitive detectors could improve their space-time resolution. PACS numbers: 78.56.-a; 72.40.+w;73.50.Pz When photo-carriers are generated locally in a non-uniformly illuminated surface or interface, a photovoltaic response can be measured parallel to the Schottky barrier between two distant lateral contacts. This behavior is known as the lateral photovoltaic effect (LPE)1–4. The LPE originates from the diffusion of carriers out of the illuminated area and it has been widely used to develo