InGaN/GaN multiple-quantum-well dual-wavelength near-white light emitting diodes

An InGaN/GaN blue light emitting diode (LED) structure and an InGaN/GaN green LED structure were grown sequentially onto the same sapphire substrate so as to achieve a nitride‐based near‐white LED. In order to avoid the thyristor effect, we choose a large 1 × 1 mm2 LED chip size, which was six times larger than that of the normal LED. It was found that we could observe a near‐white light emission with CIE color coordinates x = 0.2 and y = 0.3, when the injection current was lower than 200 mA. It was also found that the output power, luminous efficiency and color temperature of such a near‐white LED were 4.2 mW, 0.8l m/W, and 9000 K, respectively.