Quantum well intermixing enhancement using Ge-doped sol-gel derived SiO2 encapsulant layer in InGaAs/InP laser structure -: art. no. 081106

The intermixing enhancement in InGaAs/InGaAsP quantum well laser structure has been investigated using the Ge-doped sol-gel derived SiO2 encapsulant layer. A band-gap shift of similar to 64 nin has been observed from 16% Ge-doped SiO2 capped sample at the annealing temperature of 630 degrees C with effective intermixing suppression using the e-beam-evaporated SiO2 layer. Ge incorporation in the sol-gel cap reduces the mismatch of thermal expansion coefficients efficiently retaining preferential vacancies, and therefore enhancing the interdiffusion rate. The intermixed material retains a good surface morphology and preserves the optical quality as evidenced by the absence of any appreciable photoluminescence linewidth broadening. (c) 2005 American Institute Of Physics.