Study On Epitaxial Growth Of InGaAs/GaAsP Strain-compensated Quantum Well Semiconductor Laser

In order to achieve a wider spectral range of GaAs-based semiconductor quantum well lasers,InGaAs/GaAs strained quantum wells are widely used in quantum well lasers.Meanwhile,strained multiple quantum wells can achieve higher material gains,but the subsequent strain accumulation causes lattice mismatches,and the transition from layer-to-layer growth mode to layer-island growth mode brings certain difficulties to epitaxial growth.Compared with the traditional unstrained GaAs barrier,GaAsP,as a tensile strain barrier material,can improve strain accumulation in InGaAs quantum well materials and increase the critical thickness,and the quantum well laser uses higher band offset GaAsP materials as the barrier layer can improve the carrier confinement ability and high temperature characteristics.In this paper,the relationship between In composition,well width and gain wavelength in the 0.9-1.1?m In_xGa_1-xAs/GaAs strained quantum well is simulated and linearly fitted,and the relationship between different quantum well structures and accumulated strain is deduced at the same gain wavelength.The epitaxial growth of the edge-emitting semiconductor laser structure at 915 nm(0.7%)and 980 nm(1.2%)under different mismatches in the active region was carried out.Through the analysis of the test results of the uniformity and half-width of the PL,it was found that with the increase of strain Its epitaxial quality will decrease.In order to solve the problem of strain accumulation of strained quantum wells,for higher strained InGaAs quantum wells,a tensile strain barrier GaAsP is used as the strain compensation layer.At a growth temperature of 600?,the growth of In_xGa_1-xAs/GaAs_1-yP_ysingle quantum wells and multiple quantum wells were studied respectively.In order to improve the interface quality between the well and barrier,a preliminary attempt was made to insert a nano-scale thin layer of GaAs(2,4nm).Through the analysis of the PL and AFM test results and the theoretical calculation results of the critical thickness of the epitaxial layer,the thickness of the insertion layer was discussed.InGaAs/GaAs(2,4nm)/GaAsP strain-compensated multiple quantum wells(SCMQWs)overall average strain and PL half-width change law.According to the statistics of experimental data of SCMQWs with different strains,it is found that the PL spectrum half-width of the InGaAs well with medium tensile strain GaAsP_0.184(-0.6599%)barrier strain compensation layer with high-pressure strain close to 2%is significantly reduced.In addition,the influence of GaAsP composition on quantum wells in InGaAs/GaAsP SCMQWs under the same growth conditions is discussed.By changing the P composition(0,0.128,0.184,0.257)of the barrier layer GaAsP,the average strain SCMQWs samples were obtained.The calculation of the critical thickness theory and the experimental test results of PL,XRD,AFM were combined.Reveal the law of growth mode and crystal quality change.Finally,the 1.06?m InGaAs/GaAsP single quantum well semiconductor laser structure is epitaxially grown to make technical reserves and accumulation for the improvement of high-strain InGaAs quantum well semiconductor laser epitaxial growth technology.