Optical investigation of GaInP-AlGaInP quantum-well layers for high-power red laser diodes

We investigated the effect of Si diffusion on the optical properties of GaInP-AlGaInP multiple quantum wells (MQWs) grown at different growth temperatures. Photoluminescence (PL) measurements showed that the emission wavelength was shortened and the PL intensity decreased with increasing growth temperature. Secondary-ion mass spectroscopy (SIMS) measurements showed that the Si concentrations in the MQW active region were similar regardless of the growth temperature. Different growth temperatures of the MQW layers might give rise to different compositions in the MQW layers, resulting in different emission wavelengths. We also investigated the temper-aturedependent optical properties of MQW layers grown with different well thicknesses (6, 8, and 10 nm). For the sample with a well thickness of 10 nm, better crystalline quality, better GaInP-AlGaInP interfaces and higher activation energy were observed compared to other samples. However, the activation energies for all three samples were found to be smaller than the carrier confinement energy. The carrier loss in the GaInP-AlGaInP QW might be related to defects and impurities in the AlGaInP layer.