Green Luminescence from Solution-grown Junctions in GaP Containing Shallow Donors and Acceptors

Gallium phosphide diodes doped with shallow donors and acceptors that partially compensate one another in both the n- and p-regions give rise to bright green emission. This green emission is more efficient at room temperature than the so-called “A-line” emission commonly observed in lightly doped diodes. The peak energy of the green emission varies with the donor binding energy, and the emission is interpreted as a radiative donor-acceptor or a donor-valence band transition. Its intensity-voltage dependence and its current-voltage dependence are discussed for room temperature conditions. At 77°K, large shifts in peak energy were observed to accompany changes in applied voltage. Data concerning this peak shift, the intensity-voltage dependence, and the linewidth-voltage dependence are presented and discussed. Time effects and the temperature dependence of the quantum efficiency are also examined.