Four-dimensional imaging of carrier interface dynamics in p-n junctions

Abstract

Traveling a long way past the junction Diodes are central components of modern electronic circuits. They essentially consist of two semiconductors sandwiched together, with one deficient in electrons (p), the other enriched (n). Najafi et al. used ultrafast electron microscopy to study the dynamics in a silicon diode on a time scale of trillionths of a second. They discovered that when light excites the diode's charge carriers, those carriers migrate much farther past the p-n junction than standard models would imply. The authors explain the results using a ballistic transport model. Science , this issue p. 164