Performance of InGaN/GaN light-emitting diodes grown using NH3 with oxygen-containing impurities

The performance of InGaN/GaN light-emitting diodes (LEDs) fabricated using NH3 was varied by intentionally adding H2O, O2, or CO. The oxygen concentration in the active layer varied with the type of impurity, which was related to the binding energy of the impurity. When a small amount of oxygen was incorporated in the InGaN active layer without Si doping through an oxygen-containing impurity, the light output power of the LED was improved. On the other hand, the light output power of the LED gradually deteriorated with increasing oxygen concentration. The oxygen-containing impurities affected the light output power of the LEDs. When NH3 with any oxygen-containing impurities was purified using a purification system giving a guaranteed impurity concentration of less than 10 ppb, the light output power of the LED was recovered to that of the LED fabricated with pure NH3.