The dependence of electron overflow on peak emission wavelength was investigated in single-quantum-well (SQW) light-emitting diodes (LEDs) grown on the (2021), (2021), (1010), and (0001) planes. Each plane exhibited a characteristic “critical” emission wavelength where the output power of LEDs (measured at a current density of 22 A/cm2) without electron blocking layers (EBLs) decreased significantly compared with that of LEDs with EBLs. Compared with LEDs grown on the (0001) plane, LEDs grown on the (2021), (2021), and (1010) planes exhibited shorter critical wavelengths, indicating that electron overflow was inhibited in LEDs grown on orientations with reduced polarization.