Strong electroluminescence from direct band and defects in Ge n+/p shallow junctions at room temperature

2016 ◽  
Vol 108 (19) ◽  
pp. 191107 ◽  
Author(s):  
Guangyang Lin ◽  
Chen Wang ◽  
Cheng Li ◽  
Chaowen Chen ◽  
Zhiwei Huang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Shallow Junctions ◽  
Direct Band

Structural Evolution Upon Annealing of Multi-Layer Si/Fe Thin Films Prepared by Magnetron Sputtering

2007 ◽  
Vol 561-565 ◽  
pp. 1161-1164
Author(s):  
Xiao Na Li ◽  
Bing Hu ◽  
Chuang Dong ◽  
Xin Jiang
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Room Temperature ◽  
Structural Evolution ◽  
Radio Frequency Magnetron Sputtering ◽  
Transmission Electron ◽  
Direct Band ◽  
The Stability ◽  
Sputtering System

Fe/Si multi-layer films were fabricated on Si (100) substrates utilizing radio frequency magnetron sputtering system. Si/β-FeSi2 structure was found in the films after the deposition. Structural characterization of Fe-silicide sample was performed by transmission electron microscopy, to explore the dependence of the microstructure of β-FeSi2 film on the preparation parameters. It was found that β-FeSi2 particles were formed after the deposition without annealing, whose size is less than 20nm ,with a direct band-gap of 0.94eV in room temperature. After annealing at 850°C, particles grow lager, however the stability of thin films was still good.

OPTICAL ABSORPTION BEHAVIOR OF Co (II) ION DOPED PVA ASSISTED CdSe NANOPARTICLES

2013 ◽  
Vol 22 ◽  
pp. 346-350
Author(s):  
K. RAVINDRANADH ◽  
R. V. S. S. N. RAVIKUMAR ◽  
M. C. RAO
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Urbach Energy ◽  
Wavelength Region ◽  
Wide Band ◽  
Cdse Nanoparticles ◽  
Poly Vinyl Alcohol ◽  
Wide Band Gap ◽  
Direct Band ◽  
Bulk Band

CdSe is an important II-VI, n-type direct band gap semiconductor with wide band gap (bulk band gap of 2.6 eV) and an attractive host for the development of doped nanoparticles. Poly vinyl alcohol (PVA) is used as a capping agent to stabilize the CdSe nanoparticles. The optical properties of Co (II) ion doped PVA capped CdSe nanoparticles grown at room temperature are studied in the wavelength region of 200-1400 nm. The spectrum of Co (II) ion doped PVA capped CdSe nanoparticles exhibit five bands at 1185, 620, 602, 548 and 465 nm (8437, 16125, 16607, 18243 and 21499 cm-1). The bands observed at 1185, 548 and 465 nm are correspond to the three spin allowed transitions 4T1g (F) → 4T2g (F), 4T1g (F) → 4A2g (F) and 4T1g (F) → 4T1g (P) respectively. The other bands observed at 602 nm and 620 nm are assigned to spin forbidden transitions 4T1g (F) → 2T2g (G), 4T1g (F) → 2T1g (G) . The small value of the Urbach energy indicates greater stability of the prepared sample.

Direct band gap light emission and detection at room temperature in bulk germanium diodes with HfGe/Ge/TiN structure

2016 ◽  
Vol 602 ◽  
pp. 43-47 ◽  
Author(s):  
Dong Wang ◽  
Takayuki Maekura ◽  
Keisuke Yamamoto ◽  
Hiroshi Nakashima
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Light Emission ◽  
Direct Band Gap ◽  
Direct Band

Room-temperature direct band-gap electroluminescence from germanium (111)-fin light-emitting diodes

2017 ◽  
Vol 56 (3) ◽  
pp. 032102 ◽  
Author(s):  
Kazuki Tani ◽  
Shin-ichi Saito ◽  
Katsuya Oda ◽  
Makoto Miura ◽  
Yuki Wakayama ◽  
...  
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Direct Band Gap ◽  
Direct Band

Room Temperature Direct Band-Gap Emission from an Unstrained Ge P-I-N LED on Si

2011 ◽  
Vol 178-179 ◽  
pp. 25-30 ◽  
Author(s):  
Tzanimir Arguirov ◽  
Martin Kittler ◽  
Michael Oehme ◽  
Nikolay V. Abrosimov ◽  
Erich Kasper ◽  
...  
Keyword(s):  
Room Temperature ◽  
Bulk Material ◽  
Wave Length ◽  
Threading Dislocation ◽  
Strong Emission ◽  
Broad Energy Range ◽  
Threading Dislocation Density ◽  
Direct Band ◽  
Band Transition

We present a novel Ge on Si based LED with unstrained i-Ge active region. The device operates at room temperature and emits photons with energy of 0.8 eV. It basically resembles a p-i-n structure formed on a sub-micrometer thin Ge layer. The Ge layer has been grown on Si substrate by utilizing thin virtual buffer, so it becomes stress free but with high threading dislocation density. We show that such forward biased diode generates strong emission, caused by direct band to band transition in Ge. Using an InSb based detector we were able to analyze the emission spectrum in a broad energy range. We show that at low and moderate currents, features belonging to the direct and the indirect band to band electronic transitions are present which are characteristic for Ge. Clearly dominating is the direct transition related peak. Due to the missing stress-related red shift this peak appears close to the desired communication wave length of 1.55 μm. The dependence of radiation intensity on the excitation current follows a power low with exponent of 1.7, indicating that the recombination rate of the competitive nonradiative processes is relatively low. At high excitation currents features appear in the low energetic part of the spectrum. All results presented here are discussed in view of the outcome from measurements on Ge high quality bulk material. The role of the dislocation in the Ge films is discussed.

scholarly journals Indium Sulfide and Ternary In-S-O Nanowires for Optoelectronic Applications

2012 ◽  
Vol 18 (S5) ◽  
pp. 121-122 ◽  
Author(s):  
J. Bartolomé ◽  
D. Maestre ◽  
A. Cremades ◽  
J. Piqueras
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
Material Properties ◽  
Room Temperature ◽  
High Efficiency ◽  
Processing Parameters ◽  
Indium Sulfide ◽  
Direct Band Gap ◽  
Direct Band ◽  
Optoelectronic Applications

Indium sulfide (In2S3) is a promising semiconductor material for window layers in solar cell devices and other optoelectronic applications as it presents a direct band gap around 2.0 eV at room temperature, and large photosensitivity and photoconductivity. The presence of several polymorphic structures depending on the processing parameters is also of interest to tailor the required material properties for different applications. It is currently being investigated for high efficiency solar cell based on CuInS2-In2S3 heterostructures, replacing CdS layers. Few studies have been reported on nanostructured In2S3 grown by several methods.

Room temperature direct band gap emission characteristics of surfactant mediated grown compressively strained Ge films

2016 ◽  
Vol 27 (43) ◽  
pp. 435204 ◽  
Author(s):  
Ajit K Katiyar ◽  
Andreas Grimm ◽  
R Bar ◽  
Jan Schmidt ◽  
Tobias Wietler ◽  
...  
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Emission Characteristics ◽  
Direct Band Gap ◽  
Direct Band

Enhanced Free Exciton and Direct Band-Edge Emissions at Room Temperature in Ultrathin ZnO Films Grown on Si Nanopillars by Atomic Layer Deposition

2011 ◽  
Vol 3 (11) ◽  
pp. 4415-4419 ◽  
Author(s):  
Yuan-Ming Chang ◽  
Jiann Shieh ◽  
Pei-Yuan Chu ◽  
Hsin-Yi Lee ◽  
Chih-Ming Lin ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Room Temperature ◽  
Free Exciton ◽  
Atomic Layer ◽  
Band Edge ◽  
Zno Films ◽  
Layer Deposition ◽  
Direct Band

Luminescence from Germanium and Germanium on Silicon

2013 ◽  
Vol 205-206 ◽  
pp. 383-393 ◽  
Author(s):  
Tzanimir Arguirov ◽  
Martin Kittler ◽  
Michael Oehme ◽  
Nikolay V. Abrosimov ◽  
Oleg F. Vyvenko ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Excitation Level ◽  
The Other ◽  
Photoluminescence Spectra ◽  
Si Substrates ◽  
Similar Dependence ◽  
Direct Band

We present an overview on generation of direct gap photo- and electroluminescence in Ge bulk wafers, Ge thin films deposited on Si, and Ge p-i-n diodes prepared on Si substrates. We analyzed the emission in a spectral range from 0.45 eV to 0.95 eV, covering the radiation caused by direct gap transitions, the indirect one, and also the luminescence related to transition on dislocations. The temperature and excitation level strongly influence the intensities of direct and indirect photoluminescence in bulk samples. As it could be expected, high temperature and excitation favour the generation of direct gap luminescence. Intrinsic bulk Ge shows a quadratic dependence of the direct gap luminescence on the excitation and a sub-quadratic one for the indirect. The photoluminescence spectra taken from intrinsic Ge on Si layers show features related to dislocations. There are two spectral regions associated with dislocation recombination. At room temperature one is at around 0.45 eV and the other at 0.72 eV. We found strong direct gap radiation from the Ge p-i-n diodes with intrinsic, highly dislocated active area (dislocation density of about 108-1010 cm-2). There is a threshold current density of 8 kA/cm2, at which the direct band luminescence becomes a super-quadratic. The dependence of the radiation intensity on the excitation is governed by a power law with exponent of 1.7 before reaching that threshold and 4.5 after exceeding it. Above the threshold the dislocation radiation shows similar dependence on the excitation as the direct band luminescence.

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

2015 ◽  
Vol 106 (7) ◽  
pp. 071102 ◽  
Author(s):  
Dong Wang ◽  
Takayuki Maekura ◽  
Sho Kamezawa ◽  
Keisuke Yamamoto ◽  
Hiroshi Nakashima
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Metal Structure ◽  
Direct Band Gap ◽  
Direct Band
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