III(A)-(VB) Type luminescent diode

A method for producing a luminescent diode comprising providing a monocrystalline G.sub.a A.sub.s wafer substrate doped with a material of the group consisting of Si, Sn and Te, at a concentration of N.sub.D = 10.sup.18 atoms/cc, to be n+ conductive, then depositing a small p+ layer on said substrate, by a liquid epitaxy process from a non-stoichiometric melt composed of GaAs, Ga, Al and Zn with a weight ratio of 1:4.6 to 4.76:0.015 to 0.028:0.03, by cooling at a rate of 0.5.degree. to 10.degree. C per minute from an initial temperature of about 930.degree. C to a final temperature of about 780.degree. C, whereby Z.sub.n diffuses a short distance into the substrate during growth, to produce a structure of the form:

• n.sup.+ -GaAs/p -GaAs/p.sup.+ -Ga.sub.x Al.sub.1-x As,
• then subjecting the resultant structure, after separation from the melt solution, to a temperature process in a substantially hermetically closed system, at 900.degree. C to 1000.degree. C for 0.1 to 3 hours, in H.sub.2 atmosphere, whereby the Z.sub.n from the p+ region diffuses further into the substrate and results in an expanded light-emitting p-GaAs layer having an acceptor dopant profile with two dopant gradients, the greater of said gradients being toward said p+ region.