Fabrication of Single Crystal Gallium Phosphide Thin Films on Glass

• Published in: Scientific reports Vol. 7; no. 1; pp. 4643 - 6
• Main Authors: Emmer, Hal, Chen, Christopher T, Saive, Rebecca, Friedrich, Dennis, Horie, Yu, Arbabi, Amir, Faraon, Andrei, Atwater, Harry A
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 05.07.2017; Nature Publishing Group UK; Nature Portfolio
• Subjects: Gallium; Gallium arsenide; Magnesium; MATERIALS SCIENCE; Metamaterials; Nanophotonics and plasmonics; Nonlinear optics; Optical properties; Photons; Semiconductor research; Single crystals; Thin films
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-05012-w

Due to its high refractive index and low absorption coefficient, gallium phosphide is an ideal material for photonic structures targeted at the visible wavelengths. However, these properties are only realized with high quality epitaxial growth, which limits substrate choice and thus possible photonic applications. In this work, we report the fabrication of single crystal gallium phosphide thin films on transparent glass substrates via transfer bonding. GaP thin films on Si (001) and (112) grown by MOCVD are bonded to glass, and then the growth substrate is removed with a XeF vapor etch. The resulting GaP films have surface roughnesses below 1 nm RMS and exhibit room temperature band edge photoluminescence. Magnesium doping yielded p-type films with a carrier density of 1.6 × 10  cm that exhibited mobilities as high as 16 cm V s . Due to their unique optical properties, these films hold much promise for use in advanced optical devices.