The radiation performance of light-emitting diodes with hemispherical encapsulated lenses at the packaging level is analyzed by a Monte Carlo ray-tracing simulation. Based on optical and thermal considerations, a superior design for integrated LED packages is proposed and consistent trends are obtained in both simulated and experimental results. For integrated LED packages conforming to our design rules, a 7.1% enhancement of light output intensity is demonstrated and a 5.1 degrees C reduction of junction temperature given a 700 mA injection current is measured. This improvement may be of particular significance for an LED module system with higher power and/or larger arrays. (C) 2014 Elsevier Ltd. All rights reserved.