Controlled Band Gap Modulation of Hydrogenated Dilute Nitrides by SEM-Cathodoluminescence

Hydrogen is known to passivate nitrogen in dilute nitrides, such as Ga(AsN) and Ga(PN). By focusing an electron beam on the surface of hydrogenated GaAs1−xNx/GaAs (GaP1−yNy/GaP) we remove hydrogen atoms from their passivation sites, thus leading to a controlled decrease of the crystal band gap in the spatial region where the e-beam is steered. The area designated by the electron beam acts in all respects as a potential well for carriers. Cycling the samples several times between T=5 K and room temperature, the same CL images and spectra were recorded thus demonstrating the thermal stability of the H displacement process. The 100% pre hydrogenation conditions are achieved after 30–40 sec of irradiation at T=5 K.