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 degrees, 0.2 degrees, 0.4 degrees and 0.6 degrees; 0.4 degrees was found to consistently result in the narrowest peaks, with the optimal spectral purity of similar to 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 mu similar to 3.5 x 10(4) cm(2)/V s with an electron concentration of similar to 1 x 10(16).