The Role of Oxygen in p-Type InP

We have studied the influence of oxygen on the electrical and optical properties of Be- and As-doped InP. The initial p-type InP [Be,As] shows a strong deep photoluminescence (PL) band at 1.5microns. This PL-band was related to the P sub (In) antisite defect by optically-detected magnetic resonance (ODMR) measurements. As the oxygen concentration increases, the 1.5microns PL-band disappears and a new PL-band at 1micron appears. Hall effect and resistivity measurements show that an increase in oxygen concentration results in a conversion from p-type to n-type material. We attribute the disappearance of the 1.5microns PL-band to a shift of the Fermi-level and the introduction of the 1micron band to an oxygen-related center.