Fully Transparent Lateral AlN Schottky Barrier Diodes with ITO Contacts

Fully transparent lateral Aluminum Nitride (AlN) rectifiers with Indium Tin Oxide ( ITO) Ohmic and Schottky contacts offer a promising combination of optical transparency, high performance and durability, making them suitable for applications in optoelectronics and power electronics. In this work, we demonstrate fully transparent lateral AlN rectifiers with ITO contacts exhibiting turn-on voltages in the range 4.9–5.3 V and breakdown voltages up to 4 kV. On/off current ratios are between 10–100 over a reverse bias range up to 100 V. However, compared to AlN rectifiers with traditional Ti/Au contacts, the ITO-based devices exhibited higher on-resistances (5 × 10 3 –3 × 10 5 Ω· cm 2 ) and turn-on voltages (4.9–5.3 V), attributed to the ITO contact properties and defects within the AlN epitaxial layers. The maximum power figure of merit (V B 2 /Ron) was 5.6 kW · cm −2 , significantly lower than that of Ti/Au contacted rectifiers, indicating room for improvement through enhanced material quality and contact optimization.