Growth mechanism of <100> dark-line defects in high radiance GaAlAs LED´s

The dependence of the growth velocity of dark-line defects on current density, temperature and acceptor doping was investigated in the GaAlAs LED´s. The velocity depends strongly on the current density (J) and acceptor doping(carrier concentration;P). But it does not depend on the ambient temperatures(20∼250°C). The current density dependence of the velocity (VDLD) was shown as VDLD∝ J². Acceptor doping dependence was separated in to two regions; VDLD∝ p^-1/3(where 10¹⁶≤ p ≤ 5×10¹⁸cm^-3) and VDLD∝ p^-3(where p ≥ 5×10¹⁸cm^-3). The growth of DLD during the operation is presumably limited by the interactions with impurities. Slow degradation of the LED´s without dark structures was also investigated, and the extrapolated half-life in excess of 4×10⁷h was estimated.