Improved electrochemical etching for the formation of 3D p-n junction

3D p-n junction is a new kind of detector, also suggested as energy conversion device which can be adopted in high energy physics, clean energy power source and material test. The electrochemical etching process utilizing anodization has been described as a recommendable method to fabricate 3D structure for p-n junction. However, the thickness of sidewall between two adjacent pores in the structure is usually too thin for p-type silicon to accord with technological requirement of following diffusion. In this report, pulse current was employed to manufacture satisfactory microstructure p-type silicon with thick sidewall. The 3D p-n junction based on this novel structure is promising for application in photovoltaic energy conversion and detection.