Thin Sn x Ni y O z Films as p-Type Transparent Conducting Oxide and Their Application in Light-Emitting Diodes.

The development of good-quality p-type transparent conducting oxides (TCOs) is essential to realize the full potential of TCOs for transparent electronics. This study investigates various optical and electrical properties of Sn x Ni y O z under different deposition conditions to achieve high-performance p-type TCOs. We found that a film with 20% O 2 /Ar deposited at room temperature exhibits the highest p-type conductivity with a carrier concentration of 2.04 × 10 17 cm -3 , a resistivity of 14.01 Ωcm, and a Hall mobility of 7.7 cm 2 V -1 S -1 . We also studied the elemental properties of a Sn x Ni y O z film and the band alignment at the Sn x Ni y O z /InP interface and found reasonably large values of the conduction band offset (CBO) and valence band offset (VBO). Finally, we demonstrate stable light-emitting diodes (LEDs) with n-InP nanowires (NWs) conformably coated with a p-Sn x Ni y O z structure. Several films and devices were fabricated and tested over a span of 6 months, and we observed similar characteristics. This confirms the stability and reliability of the films as well as the reproducibility of the LEDs. We also investigated the temperature-dependent behavior of these LEDs and observed an additional peak due to a zinc blende/wurtzite (ZB/WZ) transition at the InP substrate and NW interface at ∼98 K and below. This study provides promising results of Sn x Ni y O z as a potential p-type TCO candidate for applications in electronics and optoelectronics.