Using silicon dioxide as device engineering parameter in the fabrication of photovoltaic cells through masked ion implantation

Abstract

The main goal of the research reported in this work was to demonstrate the use of silicon dioxide (SiO 2) as an effective device engineering parameter shaping the main electro-optical characteristics of p + −n single-crystalline silicon solar cells fabricated through low-energy masked ion implantation of boron ( 11B +) into n-wafers. It is shown experimentally that by variation of the SiO 2 mask thickness in the vicinity of the projected range R p (1) the peak responsivity wavelength λ s of the silicon photonic devices could be shifted into the visible portion of the light spectrum and (2) the junction electric field, aiding the collection of carriers in the illuminated mode, could be conveniently adjusted. The physical mechanisms underlying the peculiar behavior of photocells fabricated by 11B + implant through SiO 2 layers of variable thickness are explained in detail. The AM1 measurements performed on the test p + −n devices had shown that high-efficiency, “preferentially current-generating” solar cells could be fabricated by means of the technological approach developed, even without back contact and surface passivation.