Thin SnxNiyOz 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 SnxNiyOz under different deposition conditions to achieve high-performance p-type TCOs. We found that a film with 20% O2/Ar deposited at room temperature exhibits the highest p-type conductivity with a carrier concentration of 2.04 × 1017 cm-3, a resistivity of 14.01 Ωcm, and a Hall mobility of 7.7 cm2 V-1 S-1. We also studied the elemental properties of a SnxNiyOz film and the band alignment at the SnxNiyOz/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-SnxNiyOz 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 SnxNiyOz as a potential p-type TCO candidate for applications in electronics and optoelectronics.