Analytical modeling of Current Spreading Length in Flip chip GaN LEDs

In this paper, an Analytical model for the transparent conducting layer is developed for a Flip chip GaN LED. ITO (Indium tin oxide) layer is used as a Current Spreading Layer in the GaN flip chip LEDs and the expressions for the current spreading length are derived. The parameters that affect the CSL are investigated in detail by varying the thickness of the ITO layer. Normally, Flip chip LEDs have more Internal Quantum Efficiency than planar LEDs. The extraction efficiency of the LED can be further improved by taking into account the current spreading length. Numerical analysis and simulations are performed to investigate the advantage of these flip-chip LEDs over conventional planar LEDs.