Influence of metalorganic precursors flow interruption timing on green InGaN multiple quantum wells

Abstract

The paper reports on fully strained green light emitting InGaN/GaN multiple quantum wells, grown by metalorganic vapor phase epitaxy, using metal precursor multiple flow interruptions during InGaN quantum well growth. Optimization of the interruption timing (pulse t1 = 20 s, pause t2 = 12 s) lets us reach the integrated photoluminescence enhancement for the growth at temperature 780 ºC. The enhancement, as a function of pause duration, appeared to be pulse duration dependent: a lower enhancement can be achieved using shorter pulses with optimized relatively shorter pauses. Indium evaporation during the interruption time was interpreted as the main issue to keep the layers intact. Quantum wells revealing the highest photoluminescence enhancement were inspected for interface quality, layer thickness, growth speed, strain, surface morphology and roughness by TEM, XRD and AFM techniques, and compared with the one grown in the conventional mode.