Room temperature luminescence of passivated InGaN quantum dots formed by quantum-sized-controlled photoelectrochemical etching

摘要

Room temperature luminescence of epitaxial InGaN quantum dots (QDs) formed by quantum sized-controlled photoelectrochemical (QSC-PEC) etching and passivation layer regrowth is demonstrated. QSC-PEC etching is performed on a 7.5 nm thick In0.20Ga0.80N layer emitting at similar to 514-521 nm and with a laser diode emitting at 445 nm. Parameters such as etch bias (0.9 V and 1.5 V), laser average power (20 mW/cm 2 and 100 mW/cm(2)), and laser operating conditions (pulsed and continuous wave) are explored. QSC-PEC etching of In0.20Ga0.80N requires a minimum bias (0.9 V) and pulsed laser conditions in order to form QDs. After etching, the QDs do not exhibit photoluminescence due to defect recombination. Regrowth of passivation layers consisting of a 2 nm thick Al0.45Ga0.55N layer and a 11 nm thick GaN layer reduce the defect recombination, and room temperature photoluminescence is observed at room temperature at similar to 435-445 nm with narrow full-width at half-maximum of similar to 35 nm. Published by AIP Publishing.