<i>p</i> <i>n</i> junctions in tungsten diselenide

Abstract

p n junctions in WSe2 have been fabricated for the first time. 10–20-μm-thick p-type layers were grown epitaxially on n-type substrates by vapor transport at 1060–1070 °C in sealed ampoules. 5–10-mm2 diodes exhibit rectification ratios ∼104 for 0.5-V bias. The diode space charge is ∼10 μm wide, indicating a small gradient in the density of electrically active impurities. At room temperature the diode current is dominated by generation/recombination. The current is space-charge limited at lower temperatures.