Visible Light from a Siliconp−nJunction

When low-voltage silicon $p-n$ junctions are biased in the reverse direction to breakdown, visible light is emitted from the junction region. The effects of surface treatment on the phenomenon are discussed. Two typical light output vs reverse current curves are shown. A typical spectral distribution curve in the 1.8-3.4 ev range is shown. The observations suggest that the light results from a radiative relaxation mechanism involving the high-energy carriers produced in the avalanche breakdown process.