Improved photoluminescence of GaAs in ZnSe/GaAs heterojunctions grown by organometallic epitaxy

• Published in: Applied physics letters 1988-10, Vol.53 (14), p.1308-1310
• Main Authors: GHANDHI, S. K, TYAGI, S, VENKATASUBRAMANIAN, R
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.100005

Zinc selenide layers, grown by organometallic vapor phase epitaxy on gallium arsenide, are shown to improve the photoluminescence intensity of the gallium arsenide. The improvement in the room-temperature photoluminescence intensity is found to be as high as 190, for n-type GaAs covered with an 1100 Å ZnSe layer. An improvement of 145 was observed for p-type GaAs covered by a ZnSe layer of the same thickness. No such improvement is seen for ZnSe thicknesses exceeding 1500 Å, the calculated critical thickness for this heterojunction. The effective recombination velocity is estimated to be approximately 1×103 cm/s for the GaAs-ZnSe interface, with thin ZnSe layers. Different epitaxial structures were used to check the consistency of the calculations, and the results match reasonably well. Our findings suggest that the behavior of the ZnSe/GaAs heterojunction is similar to the AlGaAs/GaAs heterojunction. This presents the possibility of its use in GaAs device, where it should offer some advantages over the existing structures using AlGaAs.