Vapor-Doped Multislice LPE for Efficient GaP Green LED's

A single‐step liquid phase epitaxy process has been developed for the growth of efficient green light‐emitting diodes (LED's), in which all doping is accomplished from the vapor phase. The use of vapor‐phase doping increases the flexibility of the LPE process since junction formation and control of doping profiles is accomplished by regulating the composition and flow rates of the doping gases. This method has been applied to multislice growth on large area substrates (up to 38 mm in diameter). Thin melts and nearly complete utilization of the GaP initially dissolved in the melt minimize the gallium usage. Encapsulated LED's with efficiencies in the 0.10–0.15% range at 7 A/cm 2 are obtained routinely. These efficiencies are comparable to the highest values reported to date for low current operation. Efficiencies as high as 0.2% have been obtained at 7 A/cm 2 using this method. The short deposition time for this single‐step method, reproducibility, multislice capability, and minimum gallium consumption make this method economically attractive for the high level production of efficient green LED's.