An investigation into the electrical, optical, and microstructural effects of aluminum-doping amorphous indium zinc oxide via ultra-high vacuum co-sputter deposition.

Indium Zinc Oxide (IZO) has emerged as a high-potential material candidate for electronic applications involving novel flexible and transparent devices. IZO’s rapid growth can be attributed to its high carrier mobility (~40-50 cm2/Vs), room-temperature fabrication, superb transparency (>85%), and semi-/conducting capabilities [13, 14]. While IZO’s characteristically high carrier density (~1020 cm-3) has prevented immediate application as a semiconductor [15, 18], strategies to lower the carrier density into the semiconducting range have emerged (<1017 cm-3) [1,8,18]. Recently, novel doping techniques have demonstrated success in deterring IZO’s carrier generation while maintaining both its microstructural and optoelectrical properties. This study investigates the effects of doping IZO thin films with Al3+ via ultra-high vacuum co-sputter deposition. Films were fabricated at room-temperature (~25oC) implementing direct-current and radio-frequency power sources for IZO and Al3+, respectively. An effective carrier suppression of ~103 cm-3 at RF-25W was observed, as well as the enhancement of amorphous-phase stability via Al3+-inclusion in IZO.