One embodiment of the present invention provides a method for fabricating light-emitting diodes. The method includes etching grooves on a growth substrate, thereby creating mesas on the growth substrate. The method further includes fabricating on each of the mesas an indium gallium aluminum nitride (InGaAlN) multilayer structure which contains a p-type layer, a multi-quantum-well layer, and an n-type layer. In addition, the method includes depositing one or more metal substrate layers on top of the InGaAlN multilayer structure. Moreover, the method includes removing the growth substrate. Furthermore, the method includes creating electrodes on both sides of the InGaAlN multilayer structure, thereby resulting in a vertical-electrode configuration.