Characterizations of direct band gap photoluminescence and electroluminescence from epi-Ge on Si

Szu Lin Cheng, Gary Shambat, Jesse Lu, Hyun Yong Yu, Krishna Saraswat, Jelena Vuckovic, Yoshio Nishi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)


Characterizations of direct gap emission from epi-Ge through both optical and electrical pumping were studied for the application of Si compatible light sources such as on-chip optical interconnect. In-situ doping technique with PH3 during the epi-Ge growth was first applied to achieve high n-type doping concentrations. Photoluminescence (PL) measurements show that the direct band emission of Ge increases with higher doping concentration. This confirms that the Ge direct radiative recombination efficiency can be improved by band filling of electrons. A Ge n+/p light emitting diode (LED) on a Si substrate was then fabricated to study the electroluminescence (EL) properties related to the band filling. Direct band gap EL at 1.6 μm was also obtained from this Ge LED. Unlike ordinary electrically pumped devices, this LED shows a superlinear luminescence enhancement at high current. Thermal enhancement effects observed in temperature dependent EL spectra show the capability of this device to be operated at room temperature or above.

Original languageEnglish
Title of host publicationSiGe, Ge, and Related Compounds 4
Subtitle of host publicationMaterials, Processing, and Devices
PublisherElectrochemical Society Inc.
Number of pages10
ISBN (Electronic)9781607681755
ISBN (Print)9781566778251
Publication statusPublished - 2010
Externally publishedYes

Publication series

NameECS Transactions
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

ASJC Scopus subject areas

  • General Engineering


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