High efficiency CuInSe2–(CdZn)S solar cells: fabrication, results, and analysis

1989 ◽  
Vol 67 (4) ◽  
pp. 420-424
Author(s):  
S. Damaskinos ◽  
J. E. Phillips ◽  
M. Roy ◽  
R. W. Birkmire
Keyword(s):  
Physical Vapor Deposition ◽  
High Efficiency ◽  
Spectral Response ◽  
Response Analysis ◽  
Current Transport ◽  
Recombination Mechanism ◽  
Interface Recombination ◽  
Current Voltage ◽  
Solar Application ◽  
Diode Current

The CuInSe2 thin films for solar application are grown by physical vapor deposition in a standard evaporation system. Indium-doped high conductivity (CdZn)S is evaporated onto the CuInSe2 to form the junction. The CuInSe2–(CdZn)S devices require air heat treatments to achieve the highest efficiency. High-efficiency small-area devices exceeding 11% (87.5 mW/cm2, ELH, T = 32 °C) have been fabricated this way. The behavior of the devices cannot be described as a classical heterojunction dominated by interface recombination. Instead, current–voltage and spectral-response analysis show that the diode current transport is dominated by a Shockley–Read type of recombination model, with space–charge being the dominant recombination mechanism via midgap states, with an estimated concentration of 1014 cm−3.

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.

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.

A statistical study on artificially generated earthquake records

1976 ◽  
Vol 3 (1) ◽  
pp. 11-19
Author(s):  
W. K. Tso ◽  
B. P. Guru
Keyword(s):  
Statistical Study ◽  
Spectral Response ◽  
Flexible Structures ◽  
Time History ◽  
Maximum Response ◽  
Response Analysis ◽  
Seismic Region ◽  
Natural Period ◽  
Earthquake Records ◽  
Time History Response

A statistical study has been done to investigate (i) the variation of spectral responses of structures due to artificially generated earthquake records with identical statistical properties, (ii) the effect of duration of strong shaking phase of artificial earthquakes on the response of structures, and (iii) the number of earthquake records needed for time-history response analysis of a structure in a seismic region. The results indicate that the flexible structures are more sensitive to the inherent statistical variations among statistically identical earthquake records. Consequently several records must be used for time-history response analysis. A sample of eight or more records appear to provide a good estimate of mean maximum response. The duration of strong shaking can significantly affect the maximum response. Based on the results, it is suggested that for the purpose of estimating peak response, the strong shaking duration of the input earthquake motion should be at least four times the natural period of the structure. The maximum responses due to statistically identical ground motion records are observed to fit approximately the type 1 extreme value distribution. Thus, it is rationally possible to choose a design value based on the mean, standard deviation of the spectral response values and tolerable probability of exceedance.

scholarly journals Production and Electrical Properties of a CuZnAlMn(SMA)/p-Si Diode

2021 ◽  
Author(s):  
EMINE ALDIRMAZ ◽  
M. Güler ◽  
E. Güler
Keyword(s):  
Room Temperature ◽  
Schottky Contact ◽  
Phase Identification ◽  
Frequency Interval ◽  
Electrical Measurements ◽  
X Ray ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Type Semiconductor ◽  
Diode Current

Abstract In this study, the Cu-23.37%Zn-13.73%Al-2.92%Mn (at.%) alloy was used. Phase identification was performed with the Scanning electron microscope (SEM), and energy-dispersive X-ray (EDX). We observed in the austenite phase in Cu-23.37%Zn-13.73%Al-2.92%Mn (at.%) alloy. To produce a new Schottky diode, CuZnAlMn alloy was exploited as a Schottky contact on p-type semiconductor silicon substrate. To calculate the characteristics of the produced diode, current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G-V) analyzes were taken at room temperature (300 K), in the dark and under various lights. Using electrical measurements, the diode's ideality factor (n), barrier height (Φb), and other diode parameters were calculated. Besides, the conductance / capacitance-voltage (G/C-V) characteristics of the diode were studied and in a wide frequency interval at room temperature. Also, the capacitance and conductance values strongly ​​ rely on the frequency. From the present experimental results, the obtained diode can be used for optoelectronic devices.

HYBRID NANOMATERIALS FOR MULTI-SPECTRAL INFRARED PHOTODETECTION

2007 ◽  
Vol 17 (01) ◽  
pp. 165-172 ◽  
Author(s):  
ADRIENNE D. STIFF-ROBERTS
Keyword(s):  
Dark Current ◽  
Room Temperature ◽  
Spectral Response ◽  
Substrate Material ◽  
Hybrid Nanomaterials ◽  
Thermally Activated ◽  
Dopant Incorporation ◽  
Quantum Dot Infrared Photodetectors ◽  
Current Voltage ◽  
Fourier Transform Ir

Quantum dot infrared photodetectors (QDIPs) using quantum dots (QDs) grown by strained-layer epitaxy have demonstrated low dark current, multi-spectral response, high operating temperature, and infrared (IR) imaging. However, achieving near room-temperature, multi-spectral operation is a challenge due to randomness in QD properties. The ability to control dopant incorporation is important since charge carrier occupation influences dark current and IR spectral response. In this work, dopant incorporation is investigated in two classes of QDs; epitaxial InAs/GaAs QDs and CdSe colloidal QDs (CQDs) embedded in MEH-PPV conducting polymers. The long-term goal of this work is to combine these hybrid nanomaterials in a single device heterostructure to enable multi-spectral IR photodetection. Two important results towards this goal are discussed. First, by temperature-dependent dark current-voltage and polarization-dependent Fourier transform IR spectroscopy measurements in InAs/GaAs QDIPs featuring different doping schemes, we have provided experimental evidence for the important contribution of thermally-activated, defect-assisted, sequential resonant tunneling. Second, the enhanced quantum confinement and electron localization in the conduction band of CdSe / MEH-PPV nanocomposites enable intraband transitions in the mid-IR at room temperature. Further, by controlling the semiconductor substrate material, doping type, and doping level on which these nanocomposites are deposited, the intraband IR response can be tuned.

Elemental Analysis and Current-Voltage Characteristics of LiZnP and LiZnAs Samples for Solid-State Neutron Detectors

2013 ◽  
Vol 1576 ◽  
Author(s):  
Benjamin W. Montag ◽  
Michael A. Reichenberger ◽  
Kevin R. Arpin ◽  
Kyle A. Nelson ◽  
Philip B. Ugorowski ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
High Efficiency ◽  
Electrical Characterization ◽  
Atomic Emission ◽  
Bulk Single Crystal ◽  
Neutron Detectors ◽  
Background Radiations ◽  
Inductively Coupled ◽  
Current Voltage ◽  
Silver Epoxy

ABSTRACTResearch for a reliable solid-form semiconductor neutron detector continues because such a device would have greater efficiency, in a compact form, than present day gas-filled 3He and 10BF3 detectors. The 6Li(n,t)4He reaction yields a total Q value of 4.78 MeV, larger than 10B, and easily identified above background radiations. Hence, devices composed of either natural Li (nominally 7.5% 6Li) or enriched 6Li (usually 95% 6Li) may provide a semiconductor material for compact high efficiency neutron detectors. A sub-branch of the III-V semiconductors, the filled tetrahedral compounds, AIBIICV, known as Nowotny-Juza compounds, are known for their desirable cubic crystal structure, and were originally studied for photonic applications. Equimolar portions of Li, Zn, and P or As were sealed under vacuum (10-6 Torr) in quartz ampoules with a graphite lining, loaded into a compounding furnace, and heated to 560 °C to form the ternary compound, LiZnP or LiZnAs, and further annealed to promote crystallization. The chemical composition of the synthesized starting material was confirmed at Galbraith Laboratories, Inc. by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), which showed the compounds were reacted in equal ratios, 1-1-1, to form ternary compounds. Bulk single crystal samples were grown by a high temperature technique described elsewhere. Samples were cut, polished, and prepared for electrical characterization by depositing a Ti/Au contact onto one side of the one of the samples and using silver epoxy to form the other contact. Current-voltage curves were collected for a sample with silver epoxy for both anode and cathode contact, and for a sample with a Ti-Au anode contact and silver epoxy cathode contact. A much higher resistivity was calculated, 6.6 x 1010 Ω·cm, for the sample with a Ti-Au contact compared the high conductivity seen with the sample using silver epoxy contacts.

scholarly journals Effects of annealing atmosphere on the performance of Cu(InGa)Se 2 films sputtered from quaternary targets

2020 ◽  
Vol 7 (10) ◽  
pp. 200662
Author(s):  
Leng Zhang ◽  
Yongyi Yu ◽  
Jing Yu ◽  
Yaowei Wei
Keyword(s):  
Thin Film ◽  
Low Cost ◽  
Lower Amount ◽  
Annealing Atmosphere ◽  
Free Atmosphere ◽  
Recombination Mechanism ◽  
Depth Profiles ◽  
Interface Recombination ◽  
Cigs Thin Film ◽  
Device Efficiency

Quaternary sputtering without additional selenization is a low-cost alternative method for the preparation of Cu(InGa)Se 2 (CIGS) thin film for photovoltaics. However, without selenization, the device efficiency is much lower than that with selenization. To comprehensively examine this problem, we compared the morphologies, depth profiles, compositions, electrical properties and recombination mechanism of the absorbers fabricated with and without additional selenization. The results revealed that the amount of surface Se on CIGS films annealed in a Se-free atmosphere is less than that on CIGS films annealed in a Se-containing atmosphere. Additionally, the lower amount of surface Se reduced the carrier concentration, enhanced the resistivity of the CIGS film and allowed CIGS/CdS interface recombination to be the dominant recombination mechanism of CIGS device. The increase of interface recombination reduced the efficiency of the device annealed in a Se-free atmosphere.

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