Improving p-type contact characteristics by Ni-assisted annealing and effects on surface morphologic evolution of InGaN LED films grown on Si (111)

2011 ◽  
Vol 257 (20) ◽  
pp. 8675-8678 ◽  
Author(s):  
Guangxu Wang ◽  
Chuanbing Xiong ◽  
Junlin Liu ◽  
Fengyi Jiang
Keyword(s):  
Type Contact ◽  
Morphologic Evolution ◽  
P Type

Semiconductor self-assembled monolayers as selective contacts for efficient PiN perovskite solar cells

2019 ◽  
Vol 12 (1) ◽  
pp. 230-237 ◽  
Author(s):  
E. Yalcin ◽  
M. Can ◽  
C. Rodriguez-Seco ◽  
E. Aktas ◽  
R. Pudi ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Molecules ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Self Assembled Monolayers ◽  
Lead Iodide ◽  
Assembled Monolayers ◽  
Type Contact ◽  
Self Assembled ◽  
P Type

Herein, we studied the use of two different Self Assembled Monolayers (SAMs) made of semiconductor hole transport organic molecules to replace the most common p-type contact, PEDOT:PSS, in PiN methyl ammonium lead iodide perovskite solar cells (PSCs).

scholarly journals Electronic Sensing Platform (ESP) Based on Open-Gate Junction Field-Effect Transistor (OG-JFET) for Life Science Applications: Design, Modeling and Experimental Results

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7491
Author(s):  
Abbas Panahi ◽  
Deniz Sadighbayan ◽  
Ebrahim Ghafar-Zadeh
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
Comsol Multiphysics ◽  
Subtle Difference ◽  
Back Gate ◽  
Sensing Platform ◽  
Type Layer ◽  
Type Contact ◽  
Effect Transistor ◽  
P Type

This paper presents a new field-effect sensor called open-gate junction gate field-effect transistor (OG-JFET) for biosensing applications. The OG-JFET consists of a p-type channel on top of an n-type layer in which the p-type serves as the sensing conductive layer between two ohmic contacted sources and drain electrodes. The structure is novel as it is based on a junction field-effect transistor with a subtle difference in that the top gate (n-type contact) has been removed to open the space for introducing the biomaterial and solution. The channel can be controlled through a back gate, enabling the sensor’s operation without a bulky electrode inside the solution. In this research, in order to demonstrate the sensor’s functionality for chemical and biosensing, we tested OG-JFET with varying pH solutions, cell adhesion (human oral neutrophils), human exhalation, and DNA molecules. Moreover, the sensor was simulated with COMSOL Multiphysics to gain insight into the sensor operation and its ion-sensitive capability. The complete simulation procedures and the physics of pH modeling is presented here, being numerically solved in COMSOL Multiphysics software. The outcome of the current study puts forward OG-JFET as a new platform for biosensing applications.

scholarly journals Optimization of p-type contacts to InGaN-based laser diodes and light emitting diodes grown by plasma assisted molecular beam epitaxy

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Krzesimir Nowakowski-Szkudlarek ◽  
Grzegorz Muziol ◽  
Mikolaj Żak ◽  
Mateusz Hajdel ◽  
Marcin Siekacz ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Contact Layer ◽  
Light Emitting ◽  
Mg Doping ◽  
Current Voltage ◽  
Type Contact ◽  
Current Voltage Characteristics ◽  
P Type ◽  
Diode Current

We investigated the influence of the In0.17Ga0.83N:Mg contact layer grown by plasma assisted molecular beam epitaxy on the resistivity of p-type Ni/Au contacts. We demonstrate that the Schottky barrier width for p-type contact is less than 5 nm. We compare circular transmission line measurements with a p-n diode current-voltage characteristics and show that discrepancies between these two methods can occur if surface quality is deteriorated. It is found that the most efficient contacts to p-type material consist of In0.17Ga0.83N:Mg contact layer with Mg doping level as high as 2 × 1020 cm–3.

scholarly journals Tunable Electronic Properties of Graphene/g-AlN Heterostructure: The Effect of Vacancy and Strain Engineering

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1674 ◽  
Author(s):  
Xuefei Liu ◽  
Zhaofu Zhang ◽  
Zijiang Luo ◽  
Bing Lv ◽  
Zhao Ding
Keyword(s):  
Electronic Properties ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Tensile Strain ◽  
Schottky Barrier Height ◽  
Strain Engineering ◽  
Nitrogen Vacancy ◽  
First Principles Calculation ◽  
Type Contact ◽  
P Type

The structural and electronic properties of graphene/graphene-like Aluminum Nitrides monolayer (Gr/g-AlN) heterojunction with and without vacancies are systematically investigated by first-principles calculation. The results prove that Gr/g-AlN with nitrogen-vacancy (Gr/g-AlN-VN) is energy favorable with the smallest sublayer distance and binding energy. Gr/g-AlN-VN is nonmagnetic, like that in the pristine Gr/g-AlN structure, but it is different from the situation of g-AlN-VN, where a magnetic moment of 1 μB is observed. The metallic graphene acts as an electron acceptor in the Gr/g-AlN-VN and donor in Gr/g-AlN and Gr/g-AlN-VAl contacts. Schottky barrier height Φ B , n by traditional (hybrid) functional of Gr/g-AlN, Gr/g-AlN-VAl, and Gr/g-AlN-VN are calculated as 2.35 (3.69), 2.77 (3.23), and 1.10 (0.98) eV, respectively, showing that vacancies can effectively modulate the Schottky barrier height. Additionally, the biaxial strain engineering is conducted to modulate the heterojunction contact properties. The pristine Gr/g-AlN, which is a p-type Schottky contact under strain-free condition, would transform to an n-type contact when 10% compressive strain is applied. Ohmic contact is formed under a larger tensile strain. Furthermore, 7.5% tensile strain would tune the Gr/g-AlN-VN from n-type to p-type contact. These plentiful tunable natures would provide valuable guidance in fabricating nanoelectronics devices based on Gr/g-AlN heterojunctions.

The modulation of Schottky contacts of p-type graphene-GeC/GeS heterointerface

2018 ◽  
Vol 84 (3) ◽  
pp. 30101 ◽  
Author(s):  
Honglin Li ◽  
Yuting Cui ◽  
Haijun Luo
Keyword(s):  
Electric Fields ◽  
2D Materials ◽  
Schottky Contacts ◽  
Schottky Barriers ◽  
External Electric Fields ◽  
Type Contact ◽  
Interfacial States ◽  
Metal Interfaces ◽  
P Type ◽  
Vdw Interaction

n-Type contact of Schottky barriers at two-dimensional (2D) materials/metal interfaces is a usual formalization in the modern FETs applications. It is common to modulate it from n- to p-type through some specific methods. In this work, we came up with two new intrinsic p-type contacts of graphene-GeC/GeS and further tune them from p-type to n-type by external electric fields. It proved that the electronic properties of graphene and GeC/GeS can be roughly preserved for the weak van der Waals (vdW) interaction. p-Type contacts with relatively small barriers are formed at g-GeC/GeS heterointerfaces. After external electric field applied, the Schottky barrier can be effectively tuned by different external electric and the p-type contact further turns into n-type. Variation of the Schottky barriers indicated a partial pinning for interfaces of g-GeC/GeS. This is because the interfacial states between graphene and GeC/GeS hardly exists. The barrier height of g-GeC/GeS and the corresponding contact type can be flexibly tuned, which is of great importance in the design of novel transistors-based 2D materials. Searching for novel nanoscale electronic equipment based on 2D materials is a hot topic in the current study. This work would provide meaningful guidelines for nanoscale devices.

scholarly journals Effects of Co-Solvents on the Performance of PEDOT:PSS Films and Hybrid Photovoltaic Devices

2018 ◽  
Vol 8 (11) ◽  
pp. 2052 ◽  
Author(s):  
Abhishek Iyer ◽  
James Hack ◽  
David Angel Trujillo ◽  
Bo Tew ◽  
Joshua Zide ◽  
...  
Keyword(s):  
Solar Cells ◽  
Crystalline Silicon ◽  
Conductive Polymer ◽  
Current Approach ◽  
Silicon Solar Cells ◽  
Transfer Length ◽  
Type Contact ◽  
Improved Performance ◽  
Hybrid Silicon ◽  
P Type

Hybrid silicon solar cells have been fabricated by the spin coating of conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as a p-type contact on textured n-type crystalline silicon wafers. The effect of adding co-solvents, ethylene glycol (EG) and dimethyl sulphoxide (DMSO), to PEDOT:PSS improves its conductivity which translates to the improved performance of solar cells. Transfer length measurements were conducted to realize optimal contact with minimal losses between the front metal contact (silver) and PEDOT:PSS. From the conductivity and device results, a 7% EG with 0.25 wt% Triton (surfactant) blend of PEDOT:PSS is found to be optimal for these cells. This current approach with a few changes in the device architecture will pave way for the further improvement of PEDOT:PSS based hybrid silicon solar cells.

Numerical Evaluation of Forward Voltage in SiC Pin Diode with Non-Ohmic Current Component in Contact to p-Type Layer

2008 ◽  
Vol 600-603 ◽  
pp. 1035-1038
Author(s):  
Kenichi Ohtsuka ◽  
Yoichiro Tarui ◽  
Tomokatsu Watanabe ◽  
Keiko Fujihira ◽  
Yoshinori Matsuno
Keyword(s):  
Contact Resistance ◽  
Schottky Barrier ◽  
Surface Region ◽  
Current Component ◽  
Forward Voltage ◽  
Pin Diodes ◽  
Type Layer ◽  
Type Contact ◽  
P Type ◽  
Schottky Structure

Forward voltage of SiC pin diodes is evaluated by device simulation, where a p-type contact is described by Schottky barrier to a p-type surface region. The contact resistance is calculated from the comparison to I-V characteristic of Schottky structure to a p-SiC layer with a sufficiently low Schottky barrier height. Even in the relatively low contact resistance rc of 10-4 Wcm2, non-ohmic current component is observed in Schottky structure to p-SiC and the increase of forward voltage of pin diodes is fairly small. Forward voltage of pin diodes increases in the pin diodes with contact resistance rc over 10-4 Wcm2. The same behavior is also observed irrespective of a time constant of carriers, and doping concentration and thickness of a drift layer.

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