ORDERED VERSUS DISORDERED InGaP LAYERS GROWN BY LIQUID PHASE EPITAXY

We make a comparative study of the optical and structural characteristics of two InxGa1-xP(x≈0.5) films nearly lattice matched to GaAs, (here referred to as disordered type 1 sample (S1) and ordered type 2 sample (S2)). The films were grown by liquid phase epitaxy (LPE). Photoluminescence (PL) measurements were performed in a wide temperature and exciting power density range for different polarization of the emitted radiation along the [110] and [1-10] directions. Observations suggest that the InxGa1-xP layer in sample 1 is disordered, as commonly obtained in LPE growth, while in sample 2 at least a partially spontaneously ordered layer was obtained. Moreover, the energy position of the 20 K PL peak is close to the predicted band gap energy for the InGaP2 material ordered in the CuPt phase. [1].