Lee Jeong Hyuk, Lee Woong-Jhae, Kim Tai Hoon, Lee Takhee, Hong Seunghun, Kim Kee Hoon
Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea.
J Phys Condens Matter. 2017 Sep 27;29(38):384004. doi: 10.1088/1361-648X/aa7cbf. Epub 2017 Jun 30.
Transparent p-CuI/n-BaSnO heterojunction diodes were successfully fabricated by the thermal evaporation of a (1 1 1) oriented γ-phase CuI film on top of an epitaxial BaSnO (0 0 1) film grown by the pulsed laser deposition. Upon the thickness of the CuI film being increased from 30 to 400 nm, the hole carrier density was systematically reduced from 6.0 × 10 to 1.0 × 10 cm and the corresponding rectification ratio of the pn diode was proportionally enhanced from ~10 to ~10. An energy band diagram exhibiting the type-II band alignment is proposed to describe the behavior of the heterojunction diode. A shift of a built-in potential caused by the hole carrier density change in the CuI film is attributed to the thickness-dependent rectification ratio. The best performing p-CuI/n-BaSnO diode exhibited a high current rectification ratio of 6.75 × 10 at ±2 V and an ideality factor of ~1.5.
