Effect of electrical behavior of ZnO microparticles grown on porous silicon substrate

This paper reports electrical behaviors of zinc oxide (ZnO) microparticles grown on porous silicon (PS) substrates. PS is fabricated by electrochemical etching of p-type Si, and ZnO is grown on PS via carbothermal reduction of ZnO powder through chemical vapor transport and condensation method. The I-V characteristics of PS/Si and ZnO/PS/Si devices are studied under various porosities and different illumination conditions including normal day light, halogen light, UV light, and dark room. Both devices demonstrate rectifying behavior. The measured I-V curves reveal that the increment in porosity leads to decrement in the measured transient currents. The I-V characteristics significantly depend on the type of illumination. Among all illumination conditions, the highest current in PS/Si device is observed under halogen light, whereas the highest current in ZnO/PS/Si device is observed under UV illumination. The ideality factor and DC resistance measurements are also aligned with the above mentioned findings, under all illumination conditions.