Current crowding effect in lateral and vertical LED configurations: 3D simulation and characterisation

Current crowding is one of the major issue that impedes the development of the efficient GaN-based high power light emitting diode (LED). Generally, there are two types of LED configurations, namely lateral configuration and vertical configuration needed to be experimentally fabricated to study the effects of current crowding on LED electrical and optical performance. In order to minimize the cost and time required to examine the full effect of the current crowding problem inside the devices, an identical free standing active LED layers with same contact size, material and thickness for both configurations are simulated by using ISE TCAD. In this work, we found that vertical LED configuration exhibits better electrical and optical performance by 20% and 21% respectively as compared to the lateral LED. The vertical configuration exhibits a better performance due to reduced series resistance, improved current spreading and better hear dissipation.