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The effect of zinc diffusion on InGaAsP/InP single and multiple quantum well structures was studied by secondary ion mass spectrometry (sims), Auger electron spectroscopy (AES), capacitance‐voltage measurements, photoluminescence, and x‐ray diffraction. Significant interdiffusion of In and Ga is found. The structures are stale against annealing without the presence of zinc. Interdiffusion of As and P is negligible. In a multiple quantum well Zn diffusion at 500 °C causes In and Ga intermixing: The AES profiles have become flat. At higher diffusion temperatures an ordering is found such that now the Ga concentration is at a maximum in the original InP layers. This can be explained by minimization of the free energy, which is balanced by an increasse in mismatch strain energy. Photoluminescence shows the interdiffusion starts at temperatures above 420 °C. By the Zn diffusion the lattice parameter values of the InGaAsP and InP layers are changed and the average value is decreased, as was shown by x‐ray diffr...

The sign of the strain in a multiquantum well (MQW) active layer of an InGaAs/InP laser determines whether lasing occurs from the electron–heavy hole transition or from the electron‐light hole transition. Lasing from the electron‐light hole transition is reported to provide a much better performance than predicted by theory. It is concluded that this gives the best device performance, providing a higher differential gain, a lower threshold current, a record low linewidth enhancement factor of 1.5, and a K factor of 0.22 ns, potentially allowing a 3 dB modulation bandwidth of 40 GHz.

High quality quantum well structures of InGaAsP (λ=1.55 μm)/InP were grown by low‐pressure organometallic vapor phase epitaxy on 0.2° and 2° misoriented (001) InP substrates. Multiple‐line 2 K photoluminescence emission was observed for the first time from thin quantum wells of InGaAsP grown on 0.2° misoriented substrates. The multiple‐line emission is interpreted to result from half‐monolayer well width variations within one well with lateral sizes larger than the excitonic radius. Quantum wells grown on substrates with 2° misorientation showed generally wider single‐line photoluminescence emission due to well width variations within one well with lateral sizes smaller than the excitonic radius. The studied well thicknesses ranged from ≊70 A down to ≊4 A, which showed emission as short as 905 nm (1.37 eV) corresponding to a spectral upshift of 514 meV. The very high quality of the quantum wells of InGaAsP is indicated by a 2 K photoluminescence linewidth of 8.8 meV for a ≊6 A well.

Photoluminescence excitation measurements were performed on GaxIn1−xAsyP1−y/InP single quantum wells. The results were analyzed with a k⋅p approach. Using the effective masses reported in the literature, the ratio of the discontinuities in the conduction and valence band is found to be 35:65. This is in good agreement with a ratio of 37:63, obtained directly from an observed transition involving free holes.