Direct band gap electroluminescence from bulk germanium at room temperature using an asymmetric fin type metal/germanium/metal structure

Journal Article · Mon Feb 16 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4913261· OSTI ID:22412640

Wang, Dong; Maekura, Takayuki; Kamezawa, Sho ^[1]; Yamamoto, Keisuke; Nakashima, Hiroshi ^[2]

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1. Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan)
2. Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan)

We demonstrated direct band gap (DBG) electroluminescence (EL) at room temperature from n-type bulk germanium (Ge) using a fin type asymmetric lateral metal/Ge/metal structure with TiN/Ge and HfGe/Ge contacts, which was fabricated using a low temperature (<400 °C) process. Small electron and hole barrier heights were obtained for TiN/Ge and HfGe/Ge contacts, respectively. DBG EL spectrum peaked at 1.55 μm was clearly observed even at a small current density of 2.2 μA/μm. Superlinear increase in EL intensity was also observed with increasing current density, due to superlinear increase in population of elections in direct conduction band. The efficiency of hole injection was also clarified.

• OSTI ID: 22412640
• Journal Information: Applied Physics Letters, Vol. 106, Issue 7; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ASYMMETRY
CURRENT DENSITY
DIFFUSION BARRIERS
ELECTROLUMINESCENCE
ELECTRONIC STRUCTURE
ELECTRONS
ENERGY GAP
GERMANIDES
GERMANIUM
HAFNIUM COMPOUNDS
HOLES
N-TYPE CONDUCTORS
TEMPERATURE DEPENDENCE
TITANIUM NITRIDES