FERMI-LEVEL PINNING AND DIFFERENTIAL EFFICIENCY IN GAINP QUANTUM-WELLLASER-DIODES

Analysis of spontaneous emission spectra of GaInP quantum well laser d iodes above and below threshold show that the quasi-Fermi level separa tion pins within the quantum wells but not throughout the whole device structure. By reproducing the temperature and cavity length dependenc e of the external differential efficiency using these measurements it is shown that a value of internal differential efficiency which is non unity is due to current spreading and incomplete carrier injection and that the temperature dependence is due to the temperature dependence of the efficiency with which carriers are injected into the quantum we ll. (C) 1997 American Institute of Physics.