Optimization of the protocrystalline p-layer in a-Si:H-based n-i-p photodiodes

2014 ◽  
Vol 1666 ◽  
Author(s):  
Y. Vygranenko ◽  
M. Fernandes ◽  
M. Vieira ◽  
A. Sazonov
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Spectral Response ◽  
Thin Layers ◽  
Rf Power ◽  
Response Characteristics ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Peak Value ◽  
Deposition Conditions

ABSTRACTThis work reports a carbon-free, blue-enhanced a-Si:H n-i-p photodiode with an optimized protocrystalline p-layer. Although the used deposition conditions for the p-layer correspond to the microcrystalline regime, thin layers are mostly protocrystalline due to the amorphous underlying undoped layer. This conclusion is supported by Raman spectroscopy measurements. We have also found that the optical band gap of the p-layer can be varied by adjusting the rf power. By widening the band gap and tuning the impurity concentration in the p-layer, absorption and recombination losses at the p-i interface were reduced. The current-voltage, capacitance-voltage, and spectral-response characteristics of fabricated photodiodes are correlated with the doping level, optical band gap, and deposition conditions for p-layers. The optimized device exhibits a leakage current of about ∼80 pA/cm2 at 5 V reverse bias. The external quantum efficiency reaches a peak value of 92% at a wavelength of 510 nm, and, at shorter wavelengths, decreases down to 66%@400nm.

Efficient Cu(In, Ga)Se2 Based Solar Cells Prepared by Electrodeposition

2003 ◽  
Vol 763 ◽  
Author(s):  
D. Guimard ◽  
N. Bodereau ◽  
J. Kurdi ◽  
J.F. Guillemoles ◽  
D. Lincot ◽  
...  
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Open Circuit Voltage ◽  
Spectral Response ◽  
Deposition Process ◽  
Open Circuit ◽  
Response Analysis ◽  
Cell Parameters ◽  
Current Voltage ◽  
Capacitance Voltage

AbstractCuInSe2 and Cu(In, Ga)Se2 precursor layers have been prepared by electrodeposition, with morphologies suitable for device completion. These precursor films were transformed into photovoltaic quality films after thermal annealing without any post-additional vacuum deposition process. Depending on the preparation parameters annealed films with different band gaps between 1eV and 1.5 eV have been prepared. The dependence of resulting solar cell parameters has been investigated. The best efficiency achieved is about 10,2 % for a band gap of 1.45 eV. This device presents an open circuit voltage value of 740 mV, in agreement with the higher band gap value. Device characterisations (current-voltage, capacitance-voltage and spectral response analysis) have been performed. Admittance spectroscopy at room temperature indicates the presence of two acceptor traps at 0.3 and 0.43 eV from the valance band with density of the order of 2. 1017 cm-3 eV-1.

Optimization of the a-SiC p-layer in a-Si:H-based n-i-p Photodiodes

2010 ◽  
Vol 1245 ◽  
Author(s):  
Yuri Vygranenko ◽  
Andrei Sazonov ◽  
Gregory Heiler ◽  
Timothy Tredwell ◽  
Manuela Vieira ◽  
...  
Keyword(s):  
Spectral Response ◽  
Depletion Region ◽  
Electron Hole ◽  
Response Characteristics ◽  
Boron Doped ◽  
Silicon Carbon ◽  
Wavelength Sensitivity ◽  
Current Voltage ◽  
Hydrogenated Amorphous ◽  
Peak Value

AbstractOur work is aimed at enhancing the external quantum efficiency (EQE) of n-i-p photodiodes by reducing the absorption losses in the p-layer and the recombination losses in the p-i interface. We have applied boron-doped and undoped hydrogenated amorphous silicon carbon alloy (a-SiC:H) grown in hydrogen-diluted, silane-methane plasma to both the p-layer and undoped buffer layer, thus tailoring the p-i interface. The current-voltage, capacitance-voltage, and spectral-response characteristics of fabricated photodiodes are correlated with the doping level, optical band gap, and deposition conditions for a-SiC:H layers. The optimized device exhibits a leakage current of about 110 pA/cm2 at the reverse bias of 5 V, and a peak value of 89% EQE at a wavelength of 530 nm. At shorter wavelengths, the EQE decreases down to 56% at a 400 nm wavelength. Calculations of transmission/reflection losses at the front of the photodiode show that observed short-wavelength sensitivity enhancement can be attributed to improved separation of electron-hole pairs in the p-layer depletion region.

Effects of Radio-Frequency Power and Deposition Pressure on Structures and Properties of Silicon-Rich Silicon Nitride Thin Films

2020 ◽  
Vol 310 ◽  
pp. 81-87
Author(s):  
Jia Xin Sun ◽  
Bing Qing Zhou ◽  
Xin Gu
Keyword(s):  
Thin Films ◽  
Silicon Nitride ◽  
Radio Frequency ◽  
Band Gap ◽  
Optical Band Gap ◽  
Pressure Increase ◽  
Light Transmittance ◽  
Rf Power ◽  
Deposition Pressure ◽  
Average Grain Size

Silicon-rich silicon nitride thin films have been grown by plasma enhanced chemical vapor deposition (PECVD) at 13.56MHZ on glass and N-type monocrystalline silicon substrate using high purity NH3,N2 and SiH4 as reactant gas sources by changing of radio-frequency (RF) power and deposition pressure. The samples were characterized by the ultraviolet-visible (UV-UIS) light transmittance spectra, Fourier transform infrared absorption spectroscopy (FTIR) and an X-ray (XRD) diffraction, respectively. The results showed that both the RF power and deposition pressure increase promote the deposition rates. However, the increase of rf power leads to the decrease of optical band gap, the increase of refractive index, and the increase of deposition pressure leads to the widening of optical band gap. The increase of rf power leads to the increase of the silicon atoms in the thin films and the transition of the films to the silicon-rich state. As the deposition pressure increase, the probability of N atoms entering the films increase and the thin films change to a nitrogen-rich state. At a certain pressure, when the rf power is changed, the average grain size in the films decrease by XRD analysis. Based on the above analysis, both the deposition pressure and rf power have an important effect on the microstructure, and optical properties of the thin films. By properly adjusting these two parameters, the silicon-rich silicon nitride films with good density can be obtained.

Current–voltage and spectral-response characteristics of surface-activated-bonding-based InGaP/GaAs/Si hybrid triple-junction cells

2015 ◽  
Vol 54 (8S1) ◽  
pp. 08KE03 ◽  
Author(s):  
Naoteru Shigekawa ◽  
Jianbo Liang ◽  
Ryusuke Onitsuka ◽  
Takaaki Agui ◽  
Hiroyuki Juso ◽  
...  
Keyword(s):  
Triple Junction ◽  
Spectral Response ◽  
Response Characteristics ◽  
Current Voltage

scholarly journals N-образные вольт-амперные характеристики гибридных органических материалов на основе цинковых комплексов

2021 ◽  
Vol 47 (8) ◽  
pp. 3
Author(s):  
А.Н. Гусев ◽  
А.С. Мазинов ◽  
В.С. Гурченко ◽  
А.С. Тютюник ◽  
Е.В. Брага
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Infrared Spectroscopy ◽  
Electrical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Organic Materials ◽  
Zinc Complexes ◽  
Current Voltage ◽  
Current Voltage Characteristics

The current-voltage characteristics of hybrid organic materials C48H42N6O2Zn and C54H54N6O2Zn are researched. The method of obtaining, microscopy, as well as the results of infrared spectroscopy and studies of the electrical properties of the obtained thin films of these organic materials based on zinc complexes. The results of calculating the optical band gap are presented. It was found that the resulting thin-film structures have N-shaped current-voltage characteristics.

scholarly journals C-V and I-V characterisation of CdS/CdTe thin film solar cell using defect density model

2021 ◽  
Vol 18 (2) ◽  
pp. 255-270
Author(s):  
Debashish Pal ◽  
Soumee Das
Keyword(s):  
Solar Cell ◽  
Defect Density ◽  
Spectral Response ◽  
Energy Band Diagram ◽  
Density Model ◽  
Device Performance ◽  
Low Frequencies ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Impurity Doping

This paper presents a detailed study of the current-voltage (I-V) and capacitance-voltage (C-V) measurements made on a CdS/CdTe based solar cell by numerical modeling. Implementation of the simulated cell having a superstrate configuration was done with the help of SCAPS program using defect density model. The I-V characterisation includes window and absorber layer optimisation based on various factors including the impurity doping concentration, thickness and defect density. The energy band diagram, spectral response and currentvoltage plot of the optimised cell configuration are shown. C-V characterisation (Mott-Schottky analysis) of the solar cell is conducted at different low frequencies to determine the flatband potential, carrier concentration and to validate the reliability of the results. The optimum device performance was obtained when the active layer was 2 ?m thick with a doping level of 1?1015/cm3.

Light-Response Characteristics of Platinum Doped Silicon Photodetector

2013 ◽  
Vol 811 ◽  
pp. 196-199
Author(s):  
Budsara Nararug ◽  
Surada Ueamanapong ◽  
Itsara Srithanachai ◽  
Supakorn Janprapha ◽  
Ai Lada Suwanchatree ◽  
...  
Keyword(s):  
Electrical Characteristic ◽  
Light Response ◽  
Response Characteristics ◽  
Research Article ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Doped Silicon ◽  
Silicon Photodetector

The purposeof this research article is present electrical characteristic of Pt-doped silicon photodetector compare with undoped silicon photodetector. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of Pt-doped detector were investigated. In this experiment, the results of Pt-doped detector show that the dark currentisobviously decreased and the photocurrent is decreased about 9 to 10 orders. Furthermore, the capacitance characteristic isslightly increased about 0.15 pF. The effects platinum on silicon indicated the carrier in silicon have been changed.

STUDY ON OPTICAL BAND GAP OF BORON-DOPED NC-SI:H FILM

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4327-4330 ◽  
Author(s):  
WENSHENG WEI ◽  
TIANMIN WANG ◽  
CHUNXI ZHANG ◽  
GUOHUA LI ◽  
HEXIANG HAN ◽  
...  
Keyword(s):  
Band Gap ◽  
Vapor Deposition ◽  
Optical Band Gap ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Boron Doping ◽  
Rf Power ◽  
Boron Doped ◽  
Nano Crystalline ◽  
Doping Ratio

The optical band gap ( E g ) of the boron (B)-doped hydrogenated nano-crystalline silicon (nc-Si:H) films fabricated using plasma enhanced chemical vapor deposition (PECVD) was investigated in this work. The transmittance of the films were measured by spectrophotometric and the E g was evaluated utilizing three different relations for comparison, namely: α h ν= C ( h ν- E g )3, α h ν= B 0( h ν- E g )2, α h ν= C 0( h ν- E g )2. Result showed that E g decreases with the increasing of Boron doping ratio, hydrogen concentration, and substrate's temperature (Ts), respectively. E g raises up with rf power density ( P d ) from 0.4 5W.cm -2 to 0.60 w.cm -2 and then drops to the end. These can be explained for E g decreases with disorder in the films.

Analysis of the Bias Dependent Spectral Response of a-SiC:H p-i-n Photodiode

2002 ◽  
Vol 715 ◽  
Author(s):  
P. Louro ◽  
A. Fantoni ◽  
Yu. Vygranenko ◽  
M. Fernandes ◽  
M. Vieira
Keyword(s):  
Bias Voltage ◽  
Voltage Dependence ◽  
Spectral Response ◽  
Surface Recombination ◽  
Electrical Field ◽  
Field Reversal ◽  
Current Voltage ◽  
Voltage Dependent ◽  
And Inversion ◽  
Device Operation

AbstractThe bias voltage dependent spectral response (with and without steady state bias light) and the current voltage dependence has been simulated and compared to experimentally obtained values. Results show that in the heterostructures the bias voltage influences differently the field and the diffusion part of the photocurrent. The interchange between primary and secondary photocurrent (i. e. between generator and load device operation) is explained by the interaction of the field and the diffusion components of the photocurrent. A field reversal that depends on the light bias conditions (wavelength and intensity) explains the photocurrent reversal. The field reversal leads to the collapse of the diode regime (primary photocurrent) launches surface recombination at the p-i and i-n interfaces which is responsible for a double-injection regime (secondary photocurrent). Considerations about conduction band offsets, electrical field profiles and inversion layers will be taken into account to explain the optical and voltage bias dependence of the spectral response.

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