Field emission properties of silicon doped AlGaN thin film

Aluminum gallium nitride (AlGaN) thin films are prepared by pulsed laser deposition with different silicon doping concentrations from 0.5% to 2%. The field emission measurement shows that the 1% Si-doped AlGaN film has the best field emission property. Compared with undoped film, the Si-doped film has a large emission current density and a low threshold field. The increase of doping concentration can increase the carrier concentration, which will add a number of supply electrons, thereby improving greatly the FE property of AlGaN film. With the doping concentration further increasing, the defect of film increases and the electron mobility reduces. The reduction of the internal supply electron is greater than the contribution of the increase of electrons concentration, which induces the field emission performance to deteriorate. This study will provide a reliable basis for designing high-performance field emission devices.