Optimization of p-GaP reflective electrode for vertical LED

Abstract The contact resistivity and reflectance of p-GaP metal electrode play an important role in the application of GaP related optoelectronic and microelectronic devices. After annealing at 420 °C for 1 min, the lowest contact resistivity of Au/Zn contacts to p-GaP can reach 4.11×10−6 Ω·cm2, but the reflectivity of the electrode deteriorates. In this paper, Au(2)/Au(1)/Zn metal electrode was prepared on p-GaP surface by rapid annealing of Au(1)/Zn followed by evaporation of a layer of Au(2). In this process, both high reflectivity and low contact resistivity of the reflective electrode can be obtained simultaneously. After annealing at 420 °C for 1 min in nitrogen atmosphere, the specific contact resistivity of the electrode is 4.04×10−6 Ω·cm2, and the reflectivity at 630 nm is 94.5%.