Abstract
High-power InGaN single-quantum-well (SQW) structure blue/green light-emitting diodes (LEDs) with an output power of 3-5mW were fabricated. The continuous-wave operation of bluish-purple InGaN multi-quantum-well (MQW) -structure laser diodes (LDs) was achieved at room temperature with a lifetime of 35 hours. The threshold current and the voltage of the LD were 80mA and 5V, respectively. Photocurrent spectra of the InGaN SQW LEDs and MQW LDs were measured at room temperature. The energy difference between the absorption due to the excitons at n = 1 quantized energy levels and the emission energy of the blue/ green InGaN SQW LEDs and MQW LDs were 290, 570 and 190meV. Both spontaneous and stimulated emission of the LDs originated from this deep localized energy state which is equivalent to a quantum dot-like state. When the temperature or the operating current of the LDs was varied, large mode hopping of the emission wavelength was observed.
