Photovoltaic Devices from Silicon Nanoparticles

Abstract

In this paper, results of designing, fabricating and characterizing photovoltaic devices made from tailored silicon nanoparticles are shown as proof-of-principle to adopt this material into the photovoltaic sector. The silicon nanoparticles are used as active material for direct separation of the light induced charge carriers. Homo pn-junctions were constructed by silicon wafers and silicon nanocrystals, the latter doped with the opposite carrier type than the wafers. Nanocrystals were sintered on top of the wafer by a spark plasma sintering process, maintaining the nanocrystalline character. This way, the nanoparticle layers are a combined absorbing and charge separating medium. Electrical characterization measurements of the devices show a reproducible short-circuit current of up to 20 µA under illumination. A maximum short-circuit current density of 6.25 µA/cm² was realized.