Effect of group II impurity and group III native defect on disordering Cu–Pt type ordered structures in In0.5(AlxGa1−x)0.5P layers

Abstract

Cu–Pt ordering is studied with cross-sectional transmission electron microscopy in p-type, n-type, and nominally undoped InAlP and In(AlGa)P layers. These different doping conditions allow us to investigate the effect of acceptor doping with magnesium and donor doping with tellurium on removing Cu–Pt ordering in In(AlGa)P. Even more significant, however, is the ability to investigate the effect of native group III self-diffusion in p-type, n-type, and nominally undoped InAlP and In(AlGa)P layers. Our data indicate that the rapidly diffusing Mg acceptor species is less effective on removing Cu–Pt ordering than the relatively slow diffusing Te donor species. Also, our results indicate that the native group III defects and group III self-diffusion play a more important role in removing Cu–Pt ordering than either group II acceptor diffusion or group VI donor diffusion.

Sixty Thousand Hour Light Output Reliability of AlGaInP Light Emitting Diodes

“…5(b) and in Fig. 6(a) be accurately described by both (14) and (15). In other words, and in (15) must be of the form and given in (14), while and in (14) must be of the form and given in (15).…”

“…In P LED degradation is described by an equation of the form (15) where and are independent of stress time but depend on current density. At this point in the discussion, it is helpful to note that Fig.…”

“…This 60 000 hours of stress corresponds to roughly seven years of nonstop LED operation, 24 hours per day, 365 days per year, and many improvements in LED design and manufacturing control have inevitably been made over this seven-year period [4]- [15], leading to further improvements in LED reliability. We will thus also briefly discuss the reliability of some of these newer generation LEDs in this paper.…”

Donor-acceptor interactions in Al0.5In0.5P

“…As a result, the total growth time (i.e., Mg-diffusion time) for these samples was ϳ2 h or less at a nominal growth temperature of 785°C. Evidence is presented elsewhere that indicates that Al 0.5 In 0.5 P grown under these conditions exhibits Cu-Pt ordering, and such Cu-Pt ordering is known to affect the bandgap of Al 0.5 In 0.5 P. 20,21 As a result of this relationship between Cu-Pt ordering and semiconductor bandgap, 19 Cu-Pt ordering may have some small impact on the exact details of the Mg diffusion and donor-acceptor interactions that are observed in these samples, but it is unlikely to affect the general conclusions of this study. In fact, similar donoracceptor interactions have been reported in GaAs and InP epitaxial layers and bulk substrates, 4-13 which do not exhibit Cu-Pt ordering.…”

“…3,16 While this paper focuses on dopant interactions in Al 0.5 In 0.5 P, this work was part of a much broader effort to improve the understanding and control of acceptor diffusion and segregation in the p-type regions of III-V heterostructures. 3,[17][18][19][20] Since the acceptor species was thus the dopant of primary concern, we refer to the acceptor species (Mg) as the dopant species throughout this paper, and we refer to the various donor species as counterdopants.…”