Electroluminescence from ZnO/n+-Si Heterojunction

2007 ◽  
Vol 131-133 ◽  
pp. 625-628 ◽  
Author(s):  
Xiang Yang Ma ◽  
Pei Liang Chen ◽  
Dong Sheng Li ◽  
De Ren Yang
Keyword(s):  
Electron Concentration ◽  
Silicon Substrate ◽  
Forward Bias ◽  
Energy Band Diagram ◽  
Near Band Edge ◽  
Band Diagram ◽  
Zno Film ◽  
Si Substrate ◽  
Current Voltage ◽  
Current Voltage Characteristics

The ZnO/n+-Si heterojunction has been fabricated via depositing nominally undoped ZnO film by reactive sputtering on a heavily arsenic-doped (n+) silicon substrate. The sputtered ZnO film was n-type in conductivity with an electron concentration of 1.0×1018 cm-3. The current-voltage characteristics indicate that the ZnO/n+-Si heterojunction does not possess rectifying function. Under the forward bias with the negative voltage applied on the n+-Si substrate, the heterojunction emits ultraviolet and broad visible lights characteristics of near-band-edge and defect-related emissions of ZnO, respectively. The EL mechanism has been tentatively explained in terms of the energy-band diagram.

scholarly journals Формирование гетероперехода II типа в полупроводниковой структуре InAsSb/InAsSbP

2020 ◽  
Vol 62 (11) ◽  
pp. 1822
Author(s):  
В.В. Романов ◽  
Э.В. Иванов ◽  
К.Д. Моисеев
Keyword(s):  
Gas Phase ◽  
Forward Bias ◽  
Energy Band Diagram ◽  
Organometallic Compounds ◽  
Blue Shift ◽  
Type Ii ◽  
Band Diagram ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Main Emission Band

The results of studying the electroluminescent and current-voltage characteristics of the n-InAs/n-InAsSb/p-InAsSbP heterostructure grown by gas-phase epitaxy from organometallic compounds are presented. Intense electroluminescence was detected in the spectral range 0.23–0.29 eV at the temperature T = 77 K. The position of the maximum of the main emission band (h ~ 0.24 eV) showed a noticeable “blue” shift with increasing applied forward bias. Based on the performed studies, it was concluded that there is a staggered type II heterojunction at the InAs0.84Sb0.16/InAs0.32Sb0.28P0.40 heterointerface, which is confirmed by the results of the calculation of the energy band diagram.

scholarly journals Исследование механизмов токопрохождения в гетероструктуре CdS/por-Si/p-Si

2018 ◽  
Vol 52 (7) ◽  
pp. 751
Author(s):  
В.В. Трегулов ◽  
В.Г. Литвинов ◽  
А.В. Ермачихин
Keyword(s):  
Current Flow ◽  
Energy Band Diagram ◽  
Band Diagram ◽  
Current Voltage Characteristic ◽  
Semiconductor Heterostructure ◽  
Current Voltage ◽  
Recombination Processes ◽  
Flow Mechanisms ◽  
Carrier Tunneling ◽  
Space Charge Limited Currents

AbstractThe temperature dependence of the forward and reverse portions of the current–voltage characteristic and the photovoltage spectrum of a CdS/ por -Si/ p -Si semiconductor heterostructure are studied. It is found that the current-flow mechanisms are controlled by generation–recombination processes in the spacecharge region of the por -Si/ p -Si heterojunction, carrier tunneling in the por -Si film, and the model of space-charge-limited currents. A simplified version of the energy-band diagram of the heterostructure under study is proposed.

Electrical and Optical Characterisation of Homojjunction Gallium Nitride Light Emitting Diodes

1997 ◽  
Vol 482 ◽  
Author(s):  
G M Laws ◽  
J Morgan ◽  
G B Ren ◽  
I Harrison ◽  
E C Larkins ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Full Width Half Maximum ◽  
Light Emitting Diodes ◽  
Deep Level ◽  
Deep Level Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Light Emitting ◽  
Current Voltage ◽  
Current Voltage Characteristics

AbstractWe report on the fabrication and characterisation gallium nitride light emitting diodes (LEDs) grown by molecular beam epitaxy on (0001) oriented sapphire and (111)B GaAs substrates. The current voltage characteristics of the devices grown on sapphire show turn on voltages of between 4 and 5V with large on-series resistance of 600Ω; for corresponding devices grown on GaAs these parameters are between 6 and 7V and 150 Ω, respectively.Room temperature electroluminescence (EL) spectra from the GaN LEDs ,grown on sapphire substrates, show a dominant emission at 3.2 eV (397nm) with a full width half maximum (FWHM) of 335 meV which is attributed to free electron to acceptor transitions (e, A−Mg). A broad low intensity deep level emission is also observed centred at 2.4 eV (506nm). The peak of the EL from the devices grown on GaAs is at 3.1eV rather than 3.2eV. The differences between the two sets of devices are probably caused by the different device geometry.Preliminary results show that an “annealing” effect caused by electrical stressing resulted in an improvement of the EL spectra. The stressed samples show an increase in the near band edge emission intensity, a 20meV reduction in the FWHM and a significant reduction in the intensity of the deep level emission. The devices have a large 1/f noise contribution which does not appear to change after electrical stressing.

Impact of Interface Traps on Current-Voltage Characteristics of 4H-SiC Schottky-Barrier Diodes

2014 ◽  
Vol 778-780 ◽  
pp. 710-713 ◽  
Author(s):  
Hamid Amini Moghadam ◽  
Sima Dimitrijev ◽  
Ji Sheng Han
Keyword(s):  
Schottky Barrier ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Interface Traps ◽  
Barrier Heights ◽  
Current Voltage ◽  
Donor Type ◽  
Current Voltage Characteristics ◽  
Expected Values

This paper presents a physical model based on interface traps to explain both the larger barrier heights of practical Schottky diodes in comparison to the theoretically expected values and the appearance of a knee in the log I–V characteristics. According to this model, acceptor-type interface traps near the valance band increase the Schottky barrier height, which shifts the log I–V characteristic to higher forward-bias voltages. In addition to the acceptor traps, donor-type interface traps can appear near the conduction band, and when they do, they cause the knee in the log I–V characteristics as their energy level falls below the Fermi level and the charge associated with these traps changes from positive to neutral.

CURRENT–VOLTAGE CHARACTERISTICS OF THERMALLY ANNEALED Ni/n-GaAs SCHOTTKY CONTACTS

2018 ◽  
Vol 25 (04) ◽  
pp. 1850082 ◽  
Author(s):  
NEZIR YILDIRIM ◽  
ABDULMECIT TURUT ◽  
HULYA DOGAN
Keyword(s):  
Barrier Height ◽  
Forward Bias ◽  
Schottky Contacts ◽  
Current Voltage Characteristic ◽  
Gaussian Distributions ◽  
Linear Behavior ◽  
Current Voltage ◽  
Device Applications ◽  
Barrier Type ◽  
Current Voltage Characteristics

The Schottky barrier type Ni/[Formula: see text]-GaAs contacts fabricated by us were thermally annealed at 600[Formula: see text]C and 700[Formula: see text]C for 1[Formula: see text]min. The apparent barrier height [Formula: see text] and ideality factor of the diodes were calculated from the forward bias current–voltage characteristic in 60–320[Formula: see text]K range. The [Formula: see text] values for the nonannealed and 600[Formula: see text]C and 700[Formula: see text]C annealed diodes were obtained as 0.80, 0.81 and 0.67[Formula: see text]eV at 300[Formula: see text]K, respectively. Thus, it has been concluded that the reduced barrier due to the thermal annealing at 700[Formula: see text]C promises some device applications. The current preferentially flows through the lowest barrier height (BH) with the temperature due to the BH inhomogeneities. Therefore, it was seen that the [Formula: see text] versus [Formula: see text] plots for the nonannealed and annealed diodes showed the linear behavior according to Gaussian distributions.

ELECTRICAL RESISTANCE OF CRACK-FREE GaN/AlN HETEROSTRUCTURE GROWN ON Si(111)

2008 ◽  
Vol 17 (03) ◽  
pp. 299-304 ◽  
Author(s):  
L. S. CHUAH ◽  
Z. HASSAN ◽  
H. ABU HASSAN
Keyword(s):  
Electrical Resistance ◽  
Intermediate Layer ◽  
Forward Bias ◽  
Differential Resistance ◽  
Back Surface ◽  
Effusion Cell ◽  
Si Substrate ◽  
Voltage Range ◽  
Current Voltage ◽  
Current Flows

This paper presents the electrical resistance of crack-free n-GaN/AlN/n-Si(111) diodes in relation to the temperature of the Al effusion cell for the growth of AlN intermediate layer (348 nm thickness) using radio-frequency molecular beam epitaxy (RF-MBE). The thickness of the unintentionally doped n-type GaN thin film is in the range of 63–100 nm. Aluminium (300 nm thickness) was sputtered onto the n-type GaN through a metal mask, followed by the 100 nm thick titanium (Ti) capping layer to obtain an ohmic contact. The back contact was created on the back surface of the Si substrate by evaporating indium (In) followed by thermal annealing at 400°C. We will consider the above as a device on an n-type Si(111) substrate, where the electron current flows from the Si substrate to the n-type GaN top layer. It was found that the current–voltage (I–V) characteristics depend on the various deposition temperature of the Al effusion cell for the growth of the AlN intermediate layer. In the forward bias region, where the electrons flow from Si(111) to the GaN top layer, we observe a threshold voltage of approximately 0.5 V for turning on a high current. The order of differential resistance magnitude was nearly a constant in the voltage range of 1.0 to 3.0 V.

The Nature of Native and Light Induced Defect States in i-layers of High Quality a-Si:H Solar Cells Derived from Dark Forward-Bias Current-Voltage Characteristics

2005 ◽  
Vol 862 ◽  
Author(s):  
J. Deng ◽  
M. L. Albert ◽  
J. M. Pearce ◽  
R. W. Collins ◽  
C. R. Wronski
Keyword(s):  
Solar Cells ◽  
Forward Bias ◽  
Bias Current ◽  
Defect State ◽  
Defect States ◽  
High Quality ◽  
Hydrogen Dilution ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Gap States

AbstractResults are presented on the defect state distributions in intrinsic a-Si:H layers with and without hydrogen dilution in p-i-n solar cells obtained directly from the analysis of dark forwardbias current-voltage (JD-V) characteristics. It is shown that there are distinct differences in the distributions of both native and light induced defect states between the two types of i-layers. Computer simulations using these distributions are presented which show excellent agreement with the experimental results not only for the JD-V but more importantly for the bias dependent differential diode quality factor n(V) characteristics. Results are also presented on the nature of the gap states and their evolution with light induced degradation as well as their effects on the performance and stability of high quality a-Si:H solar cells.

Current transport in graphene/AlGaN/GaN vertical heterostructures probed at nanoscale

Nanoscale ◽  
2014 ◽  
Vol 6 (15) ◽  
pp. 8671-8680 ◽  
Author(s):  
Gabriele Fisichella ◽  
Giuseppe Greco ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo
Keyword(s):  
Energy Band ◽  
Energy Band Diagram ◽  
Current Transport ◽  
Band Diagram ◽  
Current Voltage ◽  
Local Current ◽  
Gan Heterostructure

Local current–voltage measurements by CAFM on AlGaN/GaN and Gr/AlGaN/GaN. Energy band diagram of the Gr/AlGaN/GaN heterostructure.

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