Atomic abruptness in InGaAsP/InP quantum well heterointerfaces grown by low-pressure organometallic vapor phase epitaxy

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 Å down to ≊4 Å, 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 Å well.