Phonon contribution to double-heterojunction laser operation

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Abstract
Laser data (77 and 300 K) are presented on two photopumped undoped metallorganic chemical vapor deposition AlxGa1−xAs ‐GaAs heterostructures with active regions consisting of: (i) a thick GaAs layer (Lz1 ∼1500 Å) coupled to an auxiliary quantum‐well array of seven small Lz2 ∼50 Å coupled GaAs layers, and (ii) a comparison single thick GaAs layer (Lz2 ∼600 Å) in the form of a conventional double heterostructure (DH). Because of the strengthening of phonon‐assisted recombination with temperature, laser operation of the bulk (Lz ≳500 Å) GaAs layers is shifted from h/ω∼Eg at 77 K to Eg −h/ωL0⩽h/ω<Eg at room temperature. This behavior of the bulk DH GaAs layers agrees with that of the reference recombination radiation observed from the auxiliary quantum‐well array (wafer ♯1), which recent work indicates is phonon assisted.