We investigate the effect of trench etching and arrayed p-electrodes in improving current spreading and the efficiency of light extraction of GaN-based vertical-structured light-emitting diodes (VLEDs). Both simulated and experimental results on the uniformities of current distribution and light emission are presented and discussed. For a 2 x 2 array VLED with a die size of 1020 x 1020 mu m(2), enhancements in light output power by 0.38% (6.03%) and wall-plug efficiency by 2.79% (232%) at 364.4 mA/mm(2) (728.9 mA/mm(2)) as compared with that of regular VLED are achieved experimentally, which are attributed to improved current spreading from the arrayed p-electrode and trench designs as well as enhanced light emission from the trench region. (C) 2015 Elsevier Ltd. All rights reserved.