High-Energy Electron and Proton Irradiation of Cu(In,Ga)Se2 Heterojunction Solar Cells

2001 ◽  
Vol 668 ◽  
Author(s):  
A. Jasenek ◽  
A. Boden ◽  
K. Weinert ◽  
M. R. Balboul ◽  
H. W. Schock ◽  
...  

ABSTRACTWe investigate radiation-induced defects in high-efficiency Cu(In,Ga)Se2/CdS/ZnO heterojunction solar cells after 1-MeV electron and 4-MeV proton irradiation. We use electron and proton fluences of more than 1018 cm−2 and up to 1014 cm−2, respectively. The irradiation experiments performed at three independent electron irradiation facilities consistently prove the superior radiation resistance of these Cu(In,Ga)Se2 devices compared to other types of solar cells. The reduction of the solar cell efficiency in all experiments is predominantly caused by a loss ΔVOC of the open circuit voltage VOC. An analytical model describes ΔVOC in terms of radiation-induced defects enhancing recombination in the Cu(In,Ga)Se2 absorber material. From our model we extract the defect introduction rates for recombination centers in Cu(In,Ga)Se2 for the respective particles and energies. Isochronal annealing steps fully recover VOC of the irradiated Cu(In,Ga)Se2 solar cells. Exposure to temperatures of approx. 400 K are sufficient to restore the initial VOC within less than 5 %, even after excessive irradiation. The annealing process displays an activation energy of EA = 1.1 eV. Admittance spectroscopy directly reveals the generation and the annealing of radiation-induced defects.

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.


Author(s):  
H. Bitam ◽  
B. Hadjoudja ◽  
Beddiaf Zaidi ◽  
C. Shakher ◽  
S. Gagui ◽  
...  

Due to increased energy intensive human activities resulting accelerated demand for electric power coupled with occurrence of natural disasters with increased frequency, intensity, and duration, it becomes essential to explore and advance renewable energy technology for sustainability of the society. Addressing the stated problem and providing a radical solution has been attempted in this study. To harvest the renewable energy, among variety of solar cells reported, a composite a-Si/CZTS photovoltaic devices has not yet been investigated. The calculated parameters for solar cell based on the new array of layers consisting of a-Si/CZTS are reported in this study. The variation of i) solar cell efficiency as a function of CZTS layer thickness, temperature, acceptor, and donor defect concentration; ii) variation of the open circuit current density as a function of temperature, open circuit voltage; iii) variation of open circuit voltage as a function of the thickness of the CZTS layer has been determined. There has been no reported study on a-Si/CZTS configuration-based solar cell, analysis of the parameters, and study to address the challenges imped efficiency of the photovoltaic device and the same has been discussed in this work. The value of the SnO2/a-Si/CZTS solar cells obtained from the simulation is 23.9 %.


2019 ◽  
Vol 10 (1) ◽  
pp. 287
Author(s):  
Samira Almalki ◽  
LePing Yu ◽  
Tom Grace ◽  
Abdulaziz S. R. Bati ◽  
Joseph G. Shapter

Carbon nanotube/silicon (CNT/Si) heterojunction solar cells represent one new architecture for photovoltaic devices. The addition of MoS2 to the devices is shown to increase the efficiency of the devices. Two structures are explored. In one case, the single wall carbon nanotubes (SWCNTs) and MoS2 flakes are mixed to make a hybrid, which is then used to make a film, while in the other case, a two layer system is used with the MoS2 deposited first followed by the SWCNTs. In all cases, the solar cell efficiency is improved largely due to significant increases in the fill factor. The rise in fill factor is due to the semiconducting nature of the MoS2, which helps with the separation of charge carriers.


2014 ◽  
Vol 665 ◽  
pp. 111-114 ◽  
Author(s):  
Ying Huang ◽  
Xiao Ming Shen ◽  
Xiao Feng Wei

In this paper, InAlN/Si single-heterojunction solar cells have been theoretically simulated based on wxAMPS software. The photovoltaic parameters, such as open circuit voltage, short circuit current, fill factor and conversion efficiency were investigated with changing the indium content and thickness of n-InAlN layer. Simulation results show that the optimum efficiency of InAlN/Si solar cells is 23.1% under AM 1.5G spectral illuminations, with the indium content and thickness of n-InAlN layer are 0.65 and 600nm, respectively. The simulation would contribute to design and fabricate high efficiency InAlN/Si solar cells in experiment.


2020 ◽  
Vol 995 ◽  
pp. 71-76
Author(s):  
Aaron Glenn ◽  
Conor Mc Loughlin ◽  
Hind Ahmed ◽  
Hoda Akbari ◽  
Subhash Chandra ◽  
...  

The main energy losses in solar cells are related to spectral losses where high energy photons are not used efficiently, and energy is lost via thermalization which reduces the solar cell’s overall efficiency. A way to tackle this is to introduce a luminescent down-shifting layer (LDS) to convert these high energy photons into a lower energy bracket helping the solar cell to absorb them and thus generating a greater power output. In this paper, lumogen dye Violet 570 has been used as LDS coated films of 10μm and 60μm placed on top of Si solar cells. The dye was incorporated into polymer films of Polyvinyl Butyral (PVB) and Polymethyl Methacrylate (PMMA) after which they were tested for their absorption, transmission and emission properties. Once optimised layers had been determined, they were deposited directly onto silicon solar cells and the external quantum efficiency (EQE) of the Si solar cells were measured with and without the LDS layers. The resulting graphs have shown an increase of up to 2.9% in the overall EQE efficiency after the lumogen films had been applied.


Nanoscale ◽  
2019 ◽  
Vol 11 (15) ◽  
pp. 7497-7505 ◽  
Author(s):  
Parvathala Reddy Narangari ◽  
Siva Krishna Karuturi ◽  
Yiliang Wu ◽  
Jennifer Wong-Leung ◽  
Kaushal Vora ◽  
...  

This work demonstrates stoichiometric Ta2O5 ultrathin layer as a novel and efficient electron-selective contact for planar InP heterojunction solar cells achieving an efficiency of 19.1% and a highest ever reported open circuit voltage of 822 mV.


2017 ◽  
Vol 373 ◽  
pp. 209-212 ◽  
Author(s):  
Yurii V. Funtikov ◽  
Leonid Yu. Dubov ◽  
Yurii V. Shtotsky ◽  
Sergey V. Stepanov

Experiments on investigation of the radiation defects produced as a result of high energy proton irradiation of single crystal Si wafers are carried out. Parameters of the proton irradiation facility are presented. It is shown that the most efficient radiation defect formation correlates with the position of the Bragg peak of ionization losses. LT spectra were measured just after irradiation and then after keeping Si samples during 3 months of at room T. We did not observe any variation of the number density of the defects, except for the 7th wafer, where most part of protons was stopped. An efficient annealing of the vacancy-type defects starts at temperatures slightly lower than 100 °C (during 10 min). Annealing at about 700 °C leads to recovering of the monoexponrntial shape of the LT spectra.


2007 ◽  
Vol 989 ◽  
Author(s):  
Florian Einsele ◽  
Phillip Johannes Rostan ◽  
Uwe Rau

AbstractWe study resistive losses at (p)c-Si/(p)Si:H/(n)ZnO heterojunction back contacts for high efficiency silicon solar cells. We find that a low tunnelling resistance for the (p)a-Si:H/(n)ZnO part of the junction requires deposition of Si:H with a high hydrogen dilution RH > 40 resulting in a highly doped μc-Si:H layer. Such a μc-Si:H layer if deposited directly on a Si wafer yields a surface recombination velocity of S  180 cm/s. Using the same layer as part of a (p)c-Si/(p)Si:H/(n)ZnO back contact in a solar cell results in an open circuit voltage Voc = 640 mV and a fill factor FF = 80 %. Insertion of an (i)a-Si-layer between the μc-Si:H and the wafer leads to a further decrease of S and, for the solar cells to an increase of VOC. However, if the thickness of this intrinsic layer exceeds a threshold of 3 nm, resistive losses lead to a degradation of the fill factor of the solar cells. These resistive losses result from a valence band offset δEV between a-Si:H and c-Si of about 600 meV. The fill factor losses overcompensate the VOC gain such that there is no benefit of the (i)a-Si:H interlayer for the overall solar cell performance when using an (i)a-Si:H/(p)uc-Si:H double layer.


2021 ◽  
Author(s):  
Venkanna Kanneboina

Abstract This paper presents the influence of defect states and thickness of interface layer on high efficiency of c-Si/a-Si:H heterojunction solar cells with higher bandgap emitter a-Si:H(p) layer by AFORSHET simulation tool. At first, the performance of Ag/ZnO/a-Si:H(p)/ a-Si:H(i)/ c-Si(n)/ a-Si:H(i)/ a-Si:H(n)/Ag heterojunction solar cells was studied by altering the thickness of a-Si:H(p) and a-Si:H(i) layers. The best values of open circuit voltage (Voc) (764.8 mV), short circuit current density (Jsc) (43.15 mA/cm2), fill factor (FF) (85.71) and efficiency(ɳ) (28.28%) were obtained at 3 nm of a-Si:H(p) and a-Si:H(i) layer. In the same structure, c-Si(n) interface was introduced in between c-Si(n) and a-Si:H(i) layer. It is found that the solar cell performance was not changed by varying defect density from 109-1014 cm-3 for thin (5 and 10 nm) interface layer and estimated values are 761.7 mV, 38.83 mA/cm2, 86.09%, 25.46% correspond to Voc, Jsc, FF, ɳ respectively. For very thick interface layer, defect density has shown huge impact on the device performance. At 1 µm, the Voc, FF and ɳ values have been changed from 760.2 to 653.2 mV, 85.9 to 80.76% and 22.94 to 18.47% for the defect density of 109 to 1014 cm-3 respectively.


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