High quality semipolar (11¯02) AlGaN/AlN quantum wells with remarkably enhanced optical transition probabilities

Adjusting the growth conditions from those for c-plane growth realizes high-quality semipolar (11¯02) AlGaN/AlN quantum wells (QWs) with atomically smooth surfaces and abrupt interfaces on AlN substrates. Upon comparing the optical properties to those of c-plane QWs using time-integrated and time-resolved photoluminescence spectroscopy, the estimated internal electric field is much smaller in (11¯02) AlGaN/AlN QWs than in c-plane QWs. Thus, (11¯02) AlGaN/AlN QWs have narrower emission line widths and remarkably faster radiative recombination lifetimes, realizing highly efficient deep ultraviolet emissions.