Effects of polarization-field tuning in GaInN light-emitting diodes

III-V nitrides form the backbone of light-emitting diode (LED) technology. However, the relevance of the very strong polarization fields in III-V nitride LEDs remains unclear. Here, we demonstrate the tuning of polarization fields by mechanical force. For compressive strain in a GaInN LED epitaxial layer, we find: (i) redistribution of intensity within the electroluminescence spectrum; (ii) a decrease in the peak efficiency at low current densities; and (iii) an increase in light-output power at high current densities. These findings show the relevance of transport effects in the efficiency droop.