A hybrid heterojunction with reverse rectifying characteristics fabricated by magnetron sputtered TiOx and plasma polymerized aniline structure

作者:Sarma Bimal K*; Pal Arup R; Bailung Heremba; Chutia Joyanti
来源:Journal of Physics D: Applied Physics , 2012, 45(27): 275401.
DOI:10.1088/0022-3727/45/27/275401

摘要

A TiOx film produced by direct current reactive magnetron sputtering without substrate heating or post-deposition annealing and a plasma polymerized aniline (PPA) structure deposited in the same reactor by a radio-frequency glow discharge without the assistance of a carrier gas are used for the fabrication of a heterojunction. The gas phase discharge is investigated by a Langmuir probe and optical emission spectroscopy. The individual layers and the heterojunction are characterized for structural and optoelectronic properties. PPA has polymer- like structure and texture and is characterized by saturated-unsaturated, branched and crosslinked networks. X-ray photoelectron spectroscopy reveals a slightly reduced TiOx surface, which exhibits near band edge luminescence. The free radicals trapped in PPA readily react with oxygen when exposed to atmosphere. The heterojunction shows reverse rectifying characteristics under dark and ultraviolet (UV) irradiation. The energy levels of TiOx and PPA might exhibit reverse band bending and electrons and holes are accumulated on both sides of the heterojunction. The charge accumulation phenomena at the interface may play a key role in the device performance of a hybrid heterojunction. The current-voltage characteristic of the heterojunction is sensitive to UV light, so the structure may be used for photo-sensing applications.

  • 出版日期2012-7-11