Analysis Of The Properties Of Strained GaInP Quantum-well Lasers

Although red semiconductor lasers have long been commercialized in China,the wavelengths of the developed lasers are mostly concentrated in the red light band over 655 nm,and the domains of the lasers are focus on data storage,entertainment indications,and biomedical applications.In recent years,the demand for short wavelength red laser chips has increased with because of the rapid development of laser display technology.The tensile strained GaInP quantum well structure is the key to achieve short-wavelength red light,and there are few studies in this field in China.Therefore,the study of tensile strained GaInP quantum well lasers becomes more and more important.In this paper,the material properties of GaInP under different strain conditions was analized theoretically.Based on the analysis,the GaInP composition and strain,quantum well thickness,quantum barrier thickness,upper waveguide layer thickness,and P-type confinement layer doping are simulated to find out the influence of impurity concentration and other important parameters on the laser performance.The simulation results show that when the quantum well composition is Ga0.575In0.425P,the thickness is 9 nm,the quantum barrier composition is(Al0.59Ga0.42)0.52In0.48,the thickness is 9 nm,and the waveguide layer composition is(Al0.59Ga0.41)0.52In0.48P,and the thickness is 120 nm,the threshold current of the laser is the smallest and the slope efficiency is the highest in the same device structure condition.The lasing wavelength meets the requirement of 642 nm wavelength for laser display.Since the doping concentration in the P-AlInP layer has a great influence on the device characteristics,the doping effect of different Cp2Mg doping source fluxes on the AlInP confinement layer in the epitaxial structure of the strained GaInP quantum well semiconductor laser is investigated in experiments.The Cp2Mg flux is selected as 6 sccm-80 sccm.The test results show that the doping concentration of the AlInP confinement layer decreases when the Cp2Mg flow rate is too low or too high.The hole concentration as high as 1.17 × 1018 cm-3 is obtained at 20 sccm Mg flow rate,and hole concentration of 2.92 × 1018 cm-3 is achieved after rapid thermal annealing in the N2 atmosphere,which is the highest doping concentrations reported to-date for the P-AlInP material.Incidentally,the research had found that the negative mismatching of the Mg-doped GaInP will decrease in heavily doped circumstance and the PL characteristics of GaInP quantum well will weaken for the increasing crystal defects caused by the large tensile strain.For the structure of MOCVD grown strained GaInP quantum well red lasers,the quantum wells were mixed by rapid thermal annealing after low energy nitrogen ion implantation,and room temperature PL spectra and variable temperature PL spectra were tested for both samples.The room temperature PL test showed that the annealing has no effect on the original wafer,and the N ion implantation does not affect the emission wavelength of the quantum well,but the annealing process found that the location of the emission peak gradually blue shifing with the increase of the annealing time.Move,maximum blue shift is 23.5 nm.PL measurements showed that although the PL characteristics of different samples at room temperature are similar,the PL characteristics under low temperature and variable temperature conditions are quite different.The qualitative analysis of the results is presented in this paper.It was found that PL spectra have both single-peak and double-peak conditions at low temperatures.It is considered that in the case of double peaks,the emission peak of the high-energy end is intrinsic recombination,and the emission peak of the low-energy end is caused by recombination of electrons in the ordered region and holes in the disordered region.