Low-angle misorientation dependence of the optical properties of InGaAs/InAlAs quantum wells

We investigate the dependence of the low-temperature photoluminescence linewidths from InP-lattice-matched InGaAs/InAlAs quantum wells on the low-angle misorientation from the (1 0 0) surface of the host InP substrate. Quantum wells were grown on InP substrates misorientated by 0°, 0.2°, 0.4° and 0.6°; 0.4° was found to consistently result in the narrowest peaks, with the optimal spectral purity of ∼4.25 meV found from a 15 nm quantum well. The width of the emission from the 15 nm quantum well was used to optimize the growth parameters. Thick layers of Si-doped InGaAs were then grown and found to have bulk, low temperature (77 K) electron mobilities up to μ∼3.5×10⁴ cm²/V s with an electron concentration of ∼1×10¹⁶.