NP Heterojunction Porous Silicon Light-Emitting Diode

1991 ◽  
Vol 256 ◽  
Author(s):  
Nader M. Kalkhoran ◽  
F. Namavar ◽  
H. P. Maruska
Keyword(s):  
Porous Silicon ◽  
Indium Tin Oxide ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Wide Bandgap ◽  
Heterojunction Diode ◽  
Light Emitting ◽  
Type Semiconductor ◽  
P Type ◽  
Bias Condition

ABSTRACTWe report the first demonstration of visible light emission from an all solid-state n-p heterojunction diode based on porous silicon. The p-type silicon was electrochemically etched in a hydrofluoric acid solution to form a porous silicon region; the n-p heterojunction diode was fabricated by depositing a wide bandgap n-type semiconductor, indium-tin-oxide (ITO), onto the surface of the porous silicon. With positive bias applied, electroluminescence was observed with a relatively narrow peak at about 580 nm. The device showed strong rectifying properties and no light emission was observed under reverse bias condition. Photoluminescence in the red, orange, yellow, and green was also observed in separate sample preparations.

Effect of Electrolyte Volume Ratio on Electroluminescence of Porous Silicon Nanostructures (PSiNs) Intensity

2013 ◽  
Vol 686 ◽  
pp. 49-55
Author(s):  
M. Ain Zubaidah ◽  
N.A. Asli ◽  
Mohamad Rusop ◽  
Saifollah Abdullah
Keyword(s):  
Porous Silicon ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Volume Ratio ◽  
Visible Range ◽  
Silicon Nanostructures ◽  
Etching Time ◽  
Light Emitting ◽  
Flat Screen ◽  
P Type

For this experiment, the main purpose of this experiment is to determine the electroluminescence of PSiNs samples with optimum electrolyte volume ratio of photo-electrochemical anodisation. PSiNs samples were prepared by photo-electrochemical anodisation by using p-type silicon substrate. For the formation of PSiNs on the silicon surface, a fixed current density (J=20 mA/cm2) and 30 minutes etching time were applied for the various electrolyte volume ratio. Volume ratio of hydrofluoric acid 48% (HF48%) and absolute ethanol (C2H5OH), HF48%:C2H5OH was used for sample A (3:1), sample B (2:1), sample C (1:1), sample D (1:2) and sample E (1:3). The light emission can be observed at visible range. The effective electroluminescence was observed for sample C. Porous silicon nanostructures light–emitting diode (PSiNs-LED) has high-potential device for future flat screen display and can be high in demand.

scholarly journals A Flexible Blue Light-Emitting Diode Based on ZnO Nanowire/Polyaniline Heterojunctions

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Y. Y. Liu ◽  
X. Y. Wang ◽  
Y. Cao ◽  
X. D. Chen ◽  
S. F. Xie ◽  
...  
Keyword(s):  
Blue Light ◽  
Indium Tin Oxide ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Blue Light Emission ◽  
Light Emitting ◽  
Novel Device ◽  
Vertically Aligned ◽  
Doped Polyaniline ◽  
P Type

An organic/inorganic light-emitting diode (LED) consisting of n-type vertically aligned ZnO nanowires (NWs) and p-type proton acid doped polyaniline (PANi) is reported. The device was fabricated on flexible indium-tin-oxide (ITO) coated polyethylene terephthalate (PET) substrate. A broad blue light emission band ranging from 390 nm to 450 nm was observed in the electroluminescence (EL) spectra of the device, which was related to the interface recombination of electrons in the conduction band of ZnO NWs and holes in the polaron level of PANi. The turn-on voltage of the device is~3.5 V, lower than most of ZnO NWs based LED devices. In combination with the easy fabrication, flexibility, low power consumption, and mechanical robustness, this novel device is very promising in the application of blue LEDs.

Structural, Surface Morphological and Photoluminescence Properties of Nanostructured Porous Silicon Material for Optoelectronics Application

2012 ◽  
Vol 584 ◽  
pp. 290-294 ◽  
Author(s):  
Jeyaprakash Pandiarajan ◽  
Natarajan Jeyakumaran ◽  
Natarajan Prithivikumaran
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Light Emission ◽  
Electrochemical Etching ◽  
Light Emitting Diode ◽  
Radiative Transition ◽  
Sem Images ◽  
Optoelectronic Application ◽  
Gap Opening ◽  
P Type

The promotion of silicon (Si) from being the key material for microelectronics to an interesting material for optoelectronic application is a consequence of the possibility to reduce its device dimensionally by a cheap and easy technique. In fact, electrochemical etching of Si under controlled conditions leads to the formation of nanocrystalline porous silicon (PS) where quantum confinement of photo excited carriers and surface species yield to a band gap opening and an increased radiative transition rate resulting in efficient light emission. In the present study, the nanostructured PS samples were prepared using anodic etching of p-type silicon. The effect of current density on structural and optical properties of PS, has been investigated. XRD studies confirm the presence of silicon nanocrystallites in the PS structure. By increasing the current density, the average estimated values of grain size are found to be decreased. SEM images indicate that the pores are surrounded by a thick columnar network of silicon walls. The observed PL spectra at room temperature for all the current densities confirm the formation of PS structures with nanocrystalline features. PL studies reveal that there is a prominent visible emission peak at 606 nm. The obtained variation of intensity in PL emission may be used for intensity varied light emitting diode applications. These studies confirm that the PS is a versatile material with potential for optoelectronics application.

A Monolithic White-Light LED Based on GaN Doped with Be

2014 ◽  
Vol 93 ◽  
pp. 264-269 ◽  
Author(s):  
Henryk Teisseyre ◽  
Michal Bockowski ◽  
Toby David Young ◽  
Szymon Grzanka ◽  
Yaroslav Zhydachevskii ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Yellow Emission ◽  
Bulk Crystals ◽  
Light Emitting ◽  
Type Conductivity ◽  
P Type ◽  
Colour Rendering

In this communication, the use of gallium nitride doped with beryllium as an efficient converter for white light emitting diode is proposed. Until now beryllium in this material was mostly studied as a potential p-type dopant. Unfortunately, the realization of p-type conductivity in such a way seems impossible. However, due to a very intensive yellow emission, bulk crystals doped with beryllium can be used as light converters. In this communication, it is demonstrated that realisation of such diode is possible and realisation of a colour rendering index is close to that necessary for white light emission.

Theory of Porous Silicon Injection Electroluminescence

1992 ◽  
Vol 283 ◽  
Author(s):  
H. Paul Maruska ◽  
F. Namavar ◽  
N. M. Kalkhoran
Keyword(s):  
Porous Silicon ◽  
Light Emission ◽  
Forward Bias ◽  
Interface States ◽  
Light Emitting ◽  
Long Term Stability ◽  
Quantum Confinement Effects ◽  
Current Path ◽  
Yellow Orange ◽  
P Type

ABSTRACTWe discuss the operation of porous silicon light-emitting diodes prepared as heterojunctions between n-type In2O3:Sn (ITO) and p-type silicon nanostructures, exhibiting quantum confinement effects. The transparent ITO affords light emission through the top surface of the device, as well as providing passivation and hence long term stability. We describe a model for the injection of minority carrier electrons into the porous silicon regions, which results in the emission of yellow-orange DC electroluminescence. A detailed study of the forward bias current-voltage characteristics of the devices will be given, which allows calculations of the densities of interface states. A tendency to pin the hole fermi energy near the neutral level, φ0, is shown to control the extraction of majority carriers. Methods for improving LED efficiency by alleviating a parasitic shunt current path through interface states will be addressed.

scholarly journals Low Cost Fabrication of Si NWs/CuI Heterostructures

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 569 ◽  
Author(s):  
Maria Lo Faro ◽  
Antonio Leonardi ◽  
Dario Morganti ◽  
Barbara Fazio ◽  
Ciro Vasi ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Light Emission ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
Copper Iodide ◽  
Light Emitting ◽  
Junction Device ◽  
Type Semiconductor ◽  
P Type ◽  
Sensitized Solar Cells

In this paper, we present the realization by a low cost approach compatible with silicon technology of new nanostructures, characterized by the presence of different materials, such as copper iodide (CuI) and silicon nanowires (Si NWs). Silicon is the principal material of the microelectronics field for its low cost, easy manufacturing and market stability. In particular, Si NWs emerged in the literature as the key materials for modern nanodevices. Copper iodide is a direct wide bandgap p-type semiconductor used for several applications as a transparent hole conducting layers for dye-sensitized solar cells, light emitting diodes and for environmental purification. We demonstrated the preparation of a solid system in which Si NWs are embedded in CuI material and the structural, electrical and optical characterization is presented. These new combined Si NWs/CuI systems have strong potentiality to obtain new nanostructures characterized by different doping, that is strategic for the possibility to realize p-n junction device. Moreover, the combination of these different materials opens the route to obtain multifunction devices characterized by promising absorption, light emission, and electrical conduction.

scholarly journals Visible Light-Driven p-Type Semiconductor Gas Sensors Based on CaFe2O4 Nanoparticles

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 850
Author(s):  
Qomaruddin Qomaruddin ◽  
Olga Casals ◽  
Andris Šutka ◽  
Tony Granz ◽  
Andreas Waag ◽  
...  
Keyword(s):  
Visible Light ◽  
Gas Sensors ◽  
Light Emitting Diode ◽  
Ethanol Exposure ◽  
Desorption Process ◽  
Light Emitting ◽  
Type Semiconductor ◽  
Visible Light Driven ◽  
Calcium Iron ◽  
P Type

In this work, we present conductometric gas sensors based on p-type calcium iron oxide (CaFe2O4) nanoparticles. CaFe2O4 is a metal oxide (MOx) with a bandgap around 1.9 eV making it a suitable candidate for visible light-activated gas sensors. Our gas sensors were tested under a reducing gas (i.e., ethanol) by illuminating them with different light-emitting diode (LED) wavelengths (i.e., 465–640 nm). Regardless of their inferior response compared to the thermally activated counterparts, the developed sensors have shown their ability to detect ethanol down to 100 ppm in a reversible way and solely with the energy provided by an LED. The highest response was reached using a blue LED (465 nm) activation. Despite some responses found even in dark conditions, it was demonstrated that upon illumination the recovery after the ethanol exposure was improved, showing that the energy provided by the LEDs is sufficient to activate the desorption process between the ethanol and the CaFe2O4 surface.

Photoluminescence Properties of Porous Silicon Nanostructures (PSiNs) with Optimum Electrolyte Volume Ratio of Photo-Electrochemical Anodization

2012 ◽  
Vol 620 ◽  
pp. 40-44 ◽  
Author(s):  
Maslihan Ain Zubaidah ◽  
N.A. Asli ◽  
S.F.M. Yusop ◽  
Mohamad Rusop ◽  
Saifollah Abdullah
Keyword(s):  
Porous Silicon ◽  
Light Emitting Diode ◽  
Volume Ratio ◽  
Electrochemical Anodization ◽  
Silicon Nanostructures ◽  
Etching Time ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
Flat Screen ◽  
P Type

Porous silicon nanostructures light-emitting diode (PSiNs-LED) will be a device for future flat screen display and can be high in demand. Main purpose of this experiment is to determine the photoluminescence properties of porous silicon nanostructures (PSiNs). PSiNs samples were prepared using photo-electrochemical anodization. P-type silicon substrate was used for this experiment. For the formation of PSiNs, a fixed current density (J=20 mA/cm2) and 30 minutes etching time was applied for the variety of electrolyte volume ratio. Volume ratio of hydrofluoric acid 48% (HF48%) and absolute ethanol (C2H5OH), HF48%:C2H5OH, were used for samples 3:1, 2:1, 1:1, 1:2 and 3:1. The effective photoluminescence properties was observed for sample C.

Enhancement in light emission and electrical efficiencies of a silicon nanocrystal light-emitting diode by indium tin oxide nanowires

2014 ◽  
Vol 105 (3) ◽  
pp. 031108 ◽  
Author(s):  
Chul Huh ◽  
Bong Kyu Kim ◽  
Chang-Geun Ahn ◽  
Chel-Jong Choi ◽  
Sang-Hyeob Kim
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Silicon Nanocrystal ◽  
Light Emitting ◽  
Oxide Nanowires

White light emission from a blue polymer light emitting diode combined with YAG:Ce3+ nanoparticles

2013 ◽  
Vol 211 (3) ◽  
pp. 651-655 ◽  
Author(s):  
Jorge Oliva ◽  
Elder De la Rosa ◽  
Luis Diaz-Torres ◽  
Anvar Zakhidov
Keyword(s):  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
White Light Emission ◽  
Light Emitting ◽  
Polymer Light Emitting Diode
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