The energy band alignment of X[sub c], Γ[sub c], and Γ[sub v] points in (Al0.7Ga0.3)0.5In0.5P/Al[sub x]In[sub 1-x]P heterostructures.

Better carrier confinement in 0.6-µm-band laser diodes can be achieved by incorporating an AlInP layer into the (Al[sub 0.7]Ga[sub 0.3])[sub 0.5]In[sub 0.5]P cladding layers. The effectiveness of this heterostructure, though, cannot be analyzed without detailed knowledge of the energy band alignment at the X[sub c], Γ[sub c], and Γ[sub υ] band extrema. We conducted photoluminescence and photoreflectance measurements at 12-100 K on (Al[sub 0.7]Ga[sub 0.3])[sub 0.5]In[sub 0.5]P/Al[sub χ]In[sub 1- χ]P heterostructures (χ=0.47-0.61) free from long-range ordering, and analyzed the results to obtain basic data on the alignment scheme. In these measurements we observed the Γo to Γ[sub υ] and the X[sub c] to Γ[sub υ] transitions in bulk Al[sub 0.53] In[sub 0.47]P and (Al[sub 0.7]Ga[sub 0.3)sub 0.5]In[sub 0.5]P alloys, the Al[sub χ]In[sub 1 - χ]P X[sub c] to (Al[sub 0.7]Ga[sub 0.3])[sub 0.5]In[sub 0.5]P Γ [sub υ]transition in (Al[sub 0.7] Ga[sub 0.3])[sub 0.5]In[sub 0.5]P/Al[sub χ]In [sub 1- χ] P superlattices, and the X[sub c] to F[sub υ] and to the Γ[sub c] to Γ[sub υ] transitions in 20-nm-wide Al[sub χ]In[sub 1 - χ] P layers in (Al[sub y]Ga[sub 1 -y ])[sub 0.5]In[sub 0.5]P/Al[sub χ]In[sub 1 - χ]P/(Al[sub y]Ga[sub 1 - y])[sub 0.5]In[sub 0.5]P double heterostructures (χ = 0.33-0.39, y =0.71.0). We found that the energy level of X[sub c] in Al[sub chi;]In[sub 1 - χ]P decreased by 0.09 eV as χ increased from 0.47 to 0.61, theX[sub c] ofAl[sub χ]In[sub 1 - χ]P crossed the γ[sub c] at 0.340 (± 0.008), and the Γ [sub upsilon;] of Al[sub χIn[sub 1 - χ] P crossed the Γυ of (Al[sub 0.7]Ga[sub 0.3])[sub 0.5]In[sub 0.5]P at χ = 0.47(± 0.01). The share of the band offset at Γ[sub c] for χ = 0.53 was 75(±3)%. [ABSTRACT FROM AUTHOR]