The electronic structure of Li₂B₄O₇(110) and Li₂B₄O₇(100)

¹ Air Force Institute of Technology, 2950 Hobson Way, Wright-Patterson Air, Force Base, OH, 45433-7765, USA
² Department of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, P.O. Box 880111, Lincoln, NE, 68588-0111, USA
³ J. Bennett Johnston Sr. Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA, 70806, USA
⁴ Institute of Physical Optics, Dragomanov 23, Lviv, 79005, Ukraine
⁵ Cincinatti Children's Hospital Medical Center, 32344 Burnet Avenue, Cincinatti, OH, USA

Corresponding author: pdowben@unl.edu

Received: 31 May 2010
Accepted: 13 August 2010
Published online: 30 November 2010

Abstract

The band structure of Li₂B₄O₇(100) and Li₂B₄O₇(110) was experimentally determined using a combination of angle-resolved photoemission and angle-resolved inverse photoemission spectroscopies. The experimental band gap depends on crystallographic direction but exceeds 8.8 eV, while the bulk band gap is believed to be in the vicinity of 9.8 eV, in qualitative agreement with expectations. The occupied bulk band structure indicates relatively large values for the hole mass; with the hole mass as significantly larger than that of the electron mass derived from the unoccupied band structure. The Li₂B₄O₇(110) surface is characterized by a very light mass image potential state and a surface state that falls within the band gap of the projected bulk band structure.