Abstract: Methods and related systems for transfer of semiconductor die and more particularly for mass transfer of semiconductor die, such as light-emitting diodes, using transfer elements are disclosed. Certain aspects relate to methods of continuous mass transfer using roller feed loops. Two carrier bars move in opposite directions, one with die and one with a substrate. The die stick to a roller and transfer from a die carrier to the substrate on a substrate carrier. In certain aspects, transfer elements may include rollers, flexible rollers, or expandable rollers. Transfer elements may further include alignment features, such as alignment pockets, that provide enhanced die alignment. In certain aspects, transfer elements may include one or more planar surfaces that rotate positions relative to the die carrier and the substrate carrier.

Abstract: Group III nitride light emitting diode (LED) structures with improved electrical performance are disclosed. A Group III nitride LED structure includes one or more n-type layers, one or more p-type layers, and an active region that includes a plurality of sequentially arranged barrier-well units. In certain embodiments, doping profiles of barrier layers of the barrier-well units are configured such that a doping concentration in some barrier-well units is different than a doping concentration in other barrier-well units. In certain embodiments, a doping profile of a particular barrier layer is non-uniform. In addition to active region configurations, the doping profiles and sequence of the n-type layers and p-type layers are configured to provide Group III nitride structures with higher efficiency, lower forward voltages, and improved forward voltage performance at elevated currents and temperatures.

Abstract: Group III nitride light emitting diode (LED) structures with improved electrical performance are disclosed. A Group III nitride LED structure includes one or more n-type layers, one or more p-type layers, and an active region that includes a plurality of sequentially arranged barrier-well units. In certain embodiments, doping profiles of barrier layers of the barrier-well units are configured such that a doping concentration in some barrier-well units is different than a doping concentration in other barrier-well units. In certain embodiments, a doping profile of a particular barrier layer is non-uniform. In addition to active region configurations, the doping profiles and sequence of the n-type layers and p-type layers are configured to provide Group III nitride structures with higher efficiency, lower forward voltages, and improved forward voltage performance at elevated currents and temperatures.