The Role of Carbon in Amorphous Silicon Nip Photodiode Sensors

1990 ◽  
Vol 192 ◽  
Author(s):  
R. L. Weisfield ◽  
C. C. Tsai
Keyword(s):  
Amorphous Silicon ◽  
Quantum Efficiency ◽  
Dark Current ◽  
Spectral Response ◽  
Pin Photodiodes ◽  
Dark Currents

ABSTRACTWe have been investigating the dark current and quantum efficiency of nip and pin photodiodes for document scanning applications. Alloying the top doped layer with carbon or making it microcrystalline was found to enhance the spectral response without causing significant deleterious effects to dark current. We also observed lower dark currents in both pin and nip(μc-Si:C:H) sensors compared to nip(a-Si:C:H) sensors, which we attribute to a more graded p-i interface in the former devices.

Modeling the Optical Quantum Efficiency of Thin Film Amorphous Silicon Solar Cells

2000 ◽  
Vol 609 ◽  
Author(s):  
Sally-anne F. Rowlands ◽  
John Livingstone ◽  
Christopher P. Lund
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Quantum Efficiency ◽  
Indium Tin Oxide ◽  
Optical Constants ◽  
Spectral Response ◽  
Good Prediction ◽  
Transmission Spectra

ABSTRACTThe optical quantum efficiency and spectral response of p-i-n thin film amorphous silicon (a-Si:H) solar cells have been modeled using software based on optical admittance analysis. The optical constants of a-Si:H and Indium Tin Oxide (ITO) thin film layers have been measured by Variable Angle Spectroscopic Ellipsometry (VASE) and used as inputs into the optical admittance analysis program in order to model cells constructed from these films.Amorphous silicon thin films and p-i-n assemblies have been deposited by glow discharge and reactive sputtering techniques. The optical constants of doped and intrinsic a-Si:H thin films were determined by VASE and the film thickness verified by Scanning Electron Microscopy studies. The optical constants of commercially available transparent conducting oxide (TCO) coated substrates have also been determined by VASE.The experimental transmission spectra of p-i-n assemblies are compared with transmission spectra that have been modeled using the measured optical constants. Results of modeling different a-Si:H solar cell structures using these materials are presented, including a study of the optimal TCO layer thickness for p-i-n a-Si:H solar cells. This work shows that optical admittance modeling gives a good prediction of the optical behavior of p-i-n assemblies, but that accurate measurements of the optical constants of the component films are required in order to model effectively the optical quantum efficiency and photocurrent.

scholarly journals Коррекция характеристик кремниевых фотодиодов путем применения ионной имплантации

2020 ◽  
Vol 54 (6) ◽  
pp. 557
Author(s):  
В.Е. Асадчиков ◽  
И.Г. Дьячкова ◽  
Д.А. Золотов ◽  
Ф.Н. Чуховский ◽  
Е.В. Никитина
Keyword(s):  
Dark Current ◽  
Proton Irradiation ◽  
Guard Ring ◽  
Structural Studies ◽  
Optimal Conditions ◽  
Order Of Magnitude ◽  
Pin Photodiodes ◽  
Dark Currents ◽  
Subsequent Thermal Annealing ◽  
Electrophysical Parameters

The paper considers the data of measurement of electrophysical parameters of silicon pin-photodiodes after implantation of defect-forming ions and subsequent heat treatment, which open a new way to reduce the dark current and increase the output of suitable devices. The data of electrophysical measurements are compared with the results of structural studies. The efficiency of proton irradiation of the periphery of n+-p transitions to protect the surface of pin-photodiodes based on high resistance silicon was experimentally established. Optimal conditions - modes of proton irradiation and subsequent thermal annealing (E = 100+200+300 Kev, D = 21016 cm-2, T = 300С, t = 2 h), at which the formation of a surface layer with optimal characteristics for achieving minimum dark currents of photosensitive sites and the guard ring occurs. The application of these modes to serial pin-photodiodes with a depth of n+ - p-transitions  3 m allowed to reduce the dark current by an order of magnitude and increase the output of suitable devices.

scholarly journals Silicon Waveguide Integrated with Germanium Photodetector for a Photonic-Integrated FBG Interrogator

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1683
Author(s):  
Hongqiang Li ◽  
Sai Zhang ◽  
Zhen Zhang ◽  
Shasha Zuo ◽  
Shanshan Zhang ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Dark Current ◽  
Reverse Bias ◽  
Spectral Response ◽  
Incident Light ◽  
Absorption Efficiency ◽  
Silicon On Insulator ◽  
Reverse Bias Voltage ◽  
Device Structure ◽  
Simulation And Optimization

We report a vertically coupled germanium (Ge) waveguide detector integrated on silicon-on-insulator waveguides and an optimized device structure through the analysis of the optical field distribution and absorption efficiency of the device. The photodetector we designed is manufactured by IMEC, and the tests show that the device has good performance. This study theoretically and experimentally explains the structure of Ge PIN and the effect of the photodetector (PD) waveguide parameters on the performance of the device. Simulation and optimization of waveguide detectors with different structures are carried out. The device’s structure, quantum efficiency, spectral response, response current, changes with incident light strength, and dark current of PIN-type Ge waveguide detector are calculated. The test results show that approximately 90% of the light is absorbed by a Ge waveguide with 20 μm Ge length and 500 nm Ge thickness. The quantum efficiency of the PD can reach 90.63%. Under the reverse bias of 1 V, 2 V and 3 V, the detector’s average responsiveness in C-band reached 1.02 A/W, 1.09 A/W and 1.16 A/W and the response time is 200 ns. The dark current is only 3.7 nA at the reverse bias voltage of −1 V. The proposed silicon-based Ge PIN PD is beneficial to the integration of the detector array for photonic integrated arrayed waveguide grating (AWG)-based fiber Bragg grating (FBG) interrogators.

Study of Dark Currents in 4H-SiC UV APDs with Separate Absorption and Multiplication Regions

2007 ◽  
Vol 556-557 ◽  
pp. 953-956
Author(s):  
Stanislav I. Soloviev ◽  
Ho Young Cha ◽  
James Grande ◽  
Peter M. Sandvik
Keyword(s):  
Leakage Current ◽  
Basal Plane ◽  
Dark Current ◽  
Threading Dislocations ◽  
Leakage Currents ◽  
Electron Beam Induced Current ◽  
Current Densities ◽  
Dark Currents ◽  
Surface Leakage

Avalanche photodiodes (APDs) based on 4H-SiC are excellent candidates to replace PMTs in the UV, particularly for harsh environment applications. Here, we report on dark current analysis of 4H-SiC APDs with separate absorption and multiplication regions. Detailed analysis of the leakage current as a function of device size showed that for a given device design, the bulk leakage component is dominant at U>600V, while surface leakage is dominant at U<600V. Electron beam induced current was also used to establish a correlation between leakage current and major types of defects in the substrate. There were two types of dislocations that could be easily distinguished in the images, including threading (spots) and basal plane (comet-like) dislocations. Using image processing software, densities of threading dislocations as well as basal plane dislocations were obtained and correlated with leakage currents of the corresponding APDs. The results suggest a strong effect of threading dislocations on dark current. Densities of basal plane dislocations were very similar in all devices tested suggesting that a role of basal plane dislocations was not dominant in leakage current of the APDs.

The role of density reduction in lithiated amorphous silicon: Molecular dynamics and ab-initio studies

2021 ◽  
Author(s):  
Jay Krishan Dora ◽  
Charchit Saraswat ◽  
Ashish Gour ◽  
Sudipto Ghosh ◽  
Natraj Yedla ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Amorphous Silicon ◽  
Density Reduction

Light-Induced Metastable Defects in a-Si:H: Towards an Understanding

1985 ◽  
Vol 49 ◽  
Author(s):  
Martin Stutzmann ◽  
Warren B. Jackson ◽  
Chuang Chuang Tsai
Keyword(s):  
Amorphous Silicon ◽  
Mechanical Stress ◽  
Hydrogenated Amorphous Silicon ◽  
Material Parameters ◽  
Kinetic Behaviour ◽  
Proposed Model ◽  
Special Cases ◽  
The Stability ◽  
Hydrogenated Amorphous

AbstractThe dependence of the creation and the annealing of metastable dangling bonds in hydrogenated amorphous silicon on various material parameters will be discussed in the context of a recently proposed model. After a brief review of the kinetic behaviour governing defect creation and annealing in undoped a- Si:H, a number of special cases will be analyzed: the influence of alloying with O, N, C, and Ge, changes introduced by doping and compensation, and the role of mechanical stress. Finally, possibilities to increase the stability of a-Si:H based devices will be examined.

The role of the blocking structure in hydrogenated amorphous silicon vidicon targets

1981 ◽  
Vol 52 (12) ◽  
pp. 7275-7280 ◽  
Author(s):  
Shunri Oda ◽  
Keishi Saito ◽  
Hisashi Tomita ◽  
Isamu Shimizu ◽  
Eiichi Inoue
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous

LIGHT-INDUCED EXCESS CONDUCTIVITY AND THE ROLE OF ARGON IN THE DEPOSITION OF DOPING-MODULATED AMORPHOUS SILICON SUPERLATTICES.

1985 ◽  
Vol 56 ◽  
Author(s):  
F.-C. Su ◽  
S. Levine ◽  
P. E. Vanier ◽  
F. J. Kampas
Keyword(s):  
Amorphous Silicon ◽  
Amorphous Semiconductor ◽  
Excess Conductivity ◽  
The Novel ◽  
Semiconductor Superlattice ◽  
Deposition Parameters ◽  
Superlattice Structures ◽  
Argon Dilution ◽  
P Type

AbstractAmorphous semiconductor superlattice structures consisting of alternating n-type and p-type doped layers of hydrogenated amorphous silicon (a-Si:H) have been made by silane glow discharge in a single chamber system. These multilayered films show the novel phenomenon of light-induced excess conductivity (LEC) associated with a metastable state having a lifetime of order of days. This report shows that the LEC effect is quite dependent on the specific details of the deposition parameters, namely dilution of the silane with inert gas, substrate temperature and layer thickness. In order to investigate the origin of the LEC effect, argon dilution was used for specific regions of the structure. This experiment shows that the slow states are distributed throughout the layers, and are not concentrated at the interfaces.

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