a,b

A P-type Zinc Oxide (ZnO) /porous-silicon photovoltaic device was fabricated to detect fast ultraviolet (UV) radiation pulses. The photovoltaic UV detector, based on the deposition of the ZnO wide-band gap semiconductor material on nanospikes silicon layer to form a heterojunction, has fast response time to the UV pulses. The current-voltage characteristic, the capacitance variation with the applied voltage and the ideality factor of the heterojunction were studied. The operation of the detector under the reverse bias of-2 volts has successfully detected an ultra fast nitrogen laser pulses at 385 (nm). The traced output signals have a rise time of 1(µsec) with photoresponsivity of abou