Field emission from nanostructured AlN/GaN films on Si substrate prepared by pulsed laser deposition

Nanostructured AlN/GaN films with different thickness are synthesized on Si substrates by pulsed laser deposition (PLD). GaN and AlN single-layer films are also deposited for comparison. It is found that the turn-on field of the nanostructured AlN/GaN films is considerably decreased 2 orders of magnitude than that of single-layer films. The improvement of field emission (FE) characteristics is attributed to the quantum structure effects, which supplies a favorable location of electron emission and enhances tunneling ability. We show that by tuning the thickness of AlN/GaN, various FE characteristics can be obtained. It indicates that the optimal thickness of the nanostructured AlN/GaN films exists for their best field emission performance.