InGaN LEDs on sapphire substrates were simulated using ISE TCAD software. In order to obtain a high output power, 15 pairs of GaN (50 nm)/Al0.27Ga0.73N (52 nm) DBR were introduced between the i-GaN and n-GaN layers. The weak output power resulting from our simulation may be related to the inhomogeneous holes distribution in the quantum wells. Also the piezoelectric field due to strains which determines the emission mechanism of InGaN based LEDs is affected by these parameters. The turn on voltage for our structure was 0.7 V and has a small change with the introduction of DBR.