Improvement of photoluminescence property of (GaAl)As double-heterostructure laser wafer with buffer layer

The effect of a buffer layer on a (GaAl)As double-heterostructure wafer is examined by a photoluminescence (PL) technique. It is found that a buffer layer improves the radiative efficiency and lasing characteristics. There exists a good correlation between the buffer-layer thickness, and the PL intensity of an active layer and the threshold current density.