Figure 2
From: Nitrogen-related intermediate band in P-rich GaNxPyAs1−x−y alloys
(a) Absorption (green lines) and photomodulated transmission (blue lines) spectra of GaNxP1−x layers with various N concentrations measured in the vicinity of E− and E− + ΔSO transitions together with low temperature photoluminescence spectra (red line). (b) Contactless electroreflectance spectra of GaNP layers (blue lines) measured in the vicinity of E+ transition. The fitting curves are shown by thick grey lines. Modulus of individual resonances are shown by thin solid black lines. Since GaNP layers are tensily strained the fundamental transition is between the light-hole band and the E− band. In our fitting the strain induced splitting between light- and heavy-hole subbands is neglected and a single resonance is used to simulate the E− and the E+ transition. (c) Absorption curve in the vicinity of absorption edge used to determine the absorption constant α 0. (d) Comparison of energies of E−, E− + ΔSO, E+, and E− + ΔSO transitions obtained from BAC model for GaNP with various N concentrations (solid lines) with experimental data (points) obtained in this work and taken from the literature26,27.
