Radiative Recombination Effects in GaSb Diodes at High Current Densities

Forward biased GaSb diodes made by diffusing zinc into n‐type GaSb show emission lines at 0.72 eV or 0.78 eV at 77 °K. At current densities of approximately 60000 A cm −2 a diode showing a d.c. emission at 0.72 eV radiates mainly at 0.78 eV. Some narrowing of the 0.72 eV line has been seen. A model to explain the observed effects in terms of the band structure of GaSb is presented and some implications of the band structure for possible laser action are discussed.