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Frontiers of Optoelectronics

Front Optoelec    2012, Vol. 5 Issue (3) : 256-260     DOI: 10.1007/s12200-012-0235-4
RESEARCH ARTICLE |
Direct band gap luminescence from Ge on Si pin diodes
E. KASPER1(), M. OEHME1, J. WERNER1, T. AGUIROV2, M. KITTLER2
1. Institut für Halbleitertechnik (IHT), University of Stuttgart, Stuttgart 70569, Germany; 2. Joint Lab IHP/BTU Cottbus, Cottbus 03013, Germany
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Abstract

Germanium (Ge) pin photodiodes show clear direct band gap emission at room temperature, as grown on bulk silicon in both photoluminescence (PL) and electroluminescence (EL). PL stems from the top contact layer with highly doped Ge because of strong absorption of visible laser light excitation (532 nm). EL stems from the recombination of injected carriers in the undoped intrinsic layer. The difference in peak positions for PL (0.73 eV) and EL (0.80 eV) is explained by band gap narrowing from high doping in n+-top layer. A superlinear increase of EL with current density is explained by a rising ratio of direct/indirect electron densities when quasi Fermi energy level rises into the conduction band. An analytical model for the direct/indirect electron density ratio is given using simplifying assumptions.

Keywords photoluminescence (PL)      electroluminescence (EL)      germanium (Ge)      direct band gap     
Corresponding Authors: KASPER E.,Email:kasper@iht.uni-stuttgart.de   
Issue Date: 05 September 2012
 Cite this article:   
M. OEHME,J. WERNER,T. AGUIROV, et al. Direct band gap luminescence from Ge on Si pin diodes[J]. Front Optoelec, 2012, 5(3): 256-260.
 URL:  
http://journal.hep.com.cn/foe/EN/10.1007/s12200-012-0235-4
http://journal.hep.com.cn/foe/EN/Y2012/V5/I3/256
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M. OEHME
J. WERNER
T. AGUIROV
M. KITTLER
E. KASPER
Fig.1  Basic scheme of Ge pin structure and of luminescence experiments. MD misfit dislocation network; TD threading dislocation; photoluminescence (PL) with 532 nm laser excitation; electroluminescence (EL) via recombination of injected electrons (e) and holes (h)
Fig.2  PL spectrum of the Ge-pin photodiode (mesa diameter: 160 μm). Main lines are assigned (from left) to dislocations, narrowed direct band gap luminescence from n+ top layer (0.73 eV), and direct band gap luminescence from intrinsic Ge (0.80 eV)
Fig.3  EL spectrum of Ge-pin photodiode. Forward biased to 200 mA; Main line (0.80 eV) is from the direct gap of intrinsic Ge
Fig.4  Occupation scheme of the Ge conduction band with direct gap (Γ). The Fermi energy is assumed to be above the L valley (see text)
nindNCBoltzmann1310
ln?(ndnind)-5.5-4.3-4.1-2.2
Tab.1  Density ratio of direct /indirect states (ln/) given as function of the normalized carrier density /. The model (Eq. (6)) is assumed with Δ = 136 meV and = 300 K
1 Klingenstein W, Schweizer H. Direct gap recombination in germanium at high excitation level and low temperature. Solid-State Electronics , 1978, 21(11-12): 1371-1374
doi: 10.1016/0038-1101(78)90210-1
2 Sun X, Liu J, Kimerling L C, Michel J. Room-temperature direct bandgap electroluminesence from Ge-on-Si light-emitting diodes. Optics Letters , 2009, 34(8): 1198-1200
doi: 10.1364/OL.34.001198 pmid:19370116
3 Cheng S L, Lu J, Shambat G, Yu H Y, Saraswat K, Vuckovic J, Nishi Y. Room temperature 16 μm electroluminescence from Ge light emitting diode on Si substrate. Optics Express , 2009, 17(12): 10019
doi: 10.1364/OE.17.010019
4 Liu J, Sun X, Kimerling L C, Michel J. Direct-gap optical gain of Ge on Si at room temperature. Optics Letters , 2010, 34(11): 1738
doi: 10.1364/OL.34.001738
5 Liu J, Sun X, Camacho-Aguilera R, Kimerling L C, Michel J. Ge-on-Si laser operating at room temperature. Optics Letters , 2010, 35(5): 679-681
doi: 10.1364/OL.35.000679 pmid:20195317
6 Jalali B, Fathpour S. Silicon photonics. Journal of Lightwave Technology , 2006, 24(12): 4600-4615
7 Soref R. Silicon photonics: a review of recent literature. Silicon , 2010, 2(1): 1-6
doi: 10.1007/s12633-010-9034-y
8 Oehme M, Werner J, Kaschel M, Kirfel O, Kasper E. Germanium waveguide photodetectors integrated on silicon with MBE. Thin Solid Films , 2008, 517(1): 137-139
doi: 10.1016/j.tsf.2008.08.062
9 Klinger S, Berroth M, Kaschel M, Oehme M, Kasper E. Ge-on-Si p-i-n photodiodes with a 3-dB bandwidth of 49 GHz. IEEE Photonics Technology Letters , 2009, 21(13): 920-922
doi: 10.1109/LPT.2009.2020510
10 Oehme M, Kaschel M, Werner J, Kirfel O, Kasper E, Schulze J. Germanium on silicon photodetectors with broad spectral range. Journal of the Electrochemical Society , 2010, 157(2): H144
doi: 10.1149/1.3261854
11 Schmid M, Oehme M, Kaschel M, Werner J, Kasper E, Schulze J. Franz-Keldysh effect in germanium p-i-n photodetectors on silicon. In: 7th IEEE International Conference on Group IV Photonics (GFP) . 2010, 329-331
12 Oehme M, Werner J, Kasper E. Molecular beam epitaxy of highly antimony doped germanium on silicon. Journal of Crystal Growth , 2008, 310(21): 4531-4534
doi: 10.1016/j.jcrysgro.2008.08.018
13 Kasper E, Oehme M, Lupaca-Schomber J. High Ge content SiGe alloys: doping and contact formation. ECS Transactions , 2008, 16(10): 893-904
doi: 10.1149/1.2986850
14 Kittler M, Aguirov T. ECS 2010, post-deadline talk
15 Klaassen D B M, Slotboom J W, de Graaff H C. Unified apparent bandgap narrowing in n- and p-type silicon. Solid-State Electronics , 1992, 35(2): 125-129
doi: 10.1016/0038-1101(92)90051-D
16 Pankove J I, Aigrain P. Optical absorption of arsenic-doped degenerate germanium. Physical Review , 1962, 126(3): 956-962
doi: 10.1103/PhysRev.126.956m
17 Jain S C, Roulston D J. A simple expression for band gap narrowing (BGN) in heavily doped Si, Ge, GaAs and GexSi1-x strained layers. Solid-State Electronics , 1991, 34(5): 453-465
doi: 10.1016/0038-1101(91)90149-S
18 Burstein E. Anomalous optical absorption limit in InSb. Physical Review , 1954, 93(3): 632-633
doi: 10.1103/PhysRev.93.632
19 Kasper E, Oehme M, Arguirov T, Werner J, Kittler M, Schulze J. Room Temperature direct Band Gap Emission from Ge p-i-n Heterojunction Photodiodes. In: 7th IEEE International Conference on Group IV Photonics Late paper , 2010
20 Kasper E, Paul D J. Silicon Integrated Quantum Circuits. Berlin: Springer Verlag, 2005
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