Synthesis and Optoelectrical Characterization of Porous Silicon Using Chemical and Electrochemical Techniques

In this report, we explained the formation and characterization of high-porosity, uniform, and stable porous silicon (PS) layers. An innovative combination of electroless and electrochemical etching of silicon was introduced using a novel parameter of delay time (Td). The electroless chemical etching was optimized by varying the delay time (Td) prior to the electrochemical process to control the uniformity of the pores. The porosity and uniformity of PS samples were enhanced by applying the optimized value of delay time. The PL spectra of porous samples were measured in room temperature. The optimized sample showed the most intense PL peak compare to the other porous samples due to its highest porosity and elevated specific surface area which enhanced the absorption coefficient of this porous surface. The optical characteristics of the optimized sample indicated the highest porosity of this sample due to the application of sufficient duration of electroless chemical etching prior to applying the pulsed current. It was found that the performance of the photodetector on optimized PS sample is much better than the other porous samples.