Effects of Hydrogen Treatment in Barrier on the Electroluminescence of Green InGaN/GaN Single-Quantum-Well Light-Emitting Diodes with V-Shaped Pits Grown on Si Substrates

摘要

Effect of hydrogen (H2) treatment during the GaN barrier growth on the electroluminescence performance of green InGaN/GaN single-quantum-well light-emitting diodes (LEDs) grown on Si substrates is experimentally investigated.We prepare two LED samples with different carrier gas compositions during the growth of GaN barrier.In the H2 free LED,the GaN barrier is grown in full nitrogen (N2) atmosphere.For the other H2 treated LED,a mixture of N2 and H2 was used as the carrier gas.It is observed that V-shaped pits decrease in size after H2 treatment by means of the scanning electron microscope.Due to the fact that the p-n junction interface would be closer to the p-GaN as a result of smaller V-shaped pits,the tunneling barrier for holes to inject into the InGaN quantum well would become thicker after H2 treatment.Hence,the external quantum efficiency of the H2 treated LED is lower compared to the H2 free LED.However,LEDs would exhibit a better leakage behavior after H2 treatment during the GaN barrier growth because of more effective blocking of the threading dislocations as a result of the H2 etching at V-shaped pits.