| 초록 |
Abnormal characteristics of breakdown and forward voltages in an InGaN/GaN multiple quantum well light-emitting diodes (LED) have been studied as a function of dopants concentration. The carrier concentration increased with the flow rate of SiH4, but decreased with that of Cp2Mg. The breakdown voltage decreased with increasing the electron density, but increased with the hole concentration. In spite of an increase in resistivity with the flow rate of Cp2Mg, the operating voltage decreased. Such an abnormal behavior is believed because of presence of Mg-H or Mg-related defects, which serve as a carrier generation site or recombination center in transition region of p-n junction in reverse voltage and forward voltage, respectively. To realize high breakdown voltage for commercial application of the GaN LED, donor concentration control is more efficient than acceptor control because a LED with heavily Mg doped GaN layer can result in an abnormal characteristic due to the Mg-related defects. |
