Reversible, Light Induced Changes in a-Si:H Films and Solar Cells

1985 ◽  
Vol 49 ◽  
Author(s):  
C. R. Wronski
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Photovoltaic Properties ◽  
Cell Structures ◽  
Wide Range ◽  
Continuous Progress ◽  
Staebler Wronski Effect ◽  
Induced Changes ◽  
Conversion Efficiencies ◽  
Term Performance

Continuous progress is being made in the conversion efficiencies of a- Si:H solar cells and efficiencies in excess of 11% have been achieved. Because of these advances and the development of a-Si:H cell technologies there is an increased interest in the long term performance of a-Si:H cells and the mechanisms responsible for their degradation. The reversible light-induced changes in a-Si:H solar cells are generally associated with the Staebler-Wronski effect (SWE) (1). This effect has been studied on a wide range of a-Si:H materials using a variety of different experimental techniques and this talk reviews the results that have been obtained on a- Si:H films and solar cells (2). It discusses in greater detail recent studies on a-Si:H solar cell structures in which simultanous measurements have been made on the changes in both the photovoltaic properties as well as their electronic properties and densities of gap states. In particular it focuses on several results obtained with semitransparent metal-undoped a-Si:H Schottky barrier solar cell structures (3).

The Light Induced Changes in A-Si: H Materials and Solar Cells—Where We are Now

1997 ◽  
Vol 467 ◽  
Author(s):  
C. R. Wronski
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Paper Briefly ◽  
Cell Structures ◽  
Large Effort ◽  
Induced Changes ◽  
The Impact ◽  
Made In

ABSTRACTThe quest for understanding and especially controlling the reversible light induced changes in a-Si:H based materials has been ongoing for the last twenty years. This has been accompanied by a corresponding large effort in minimizing their effects on more efficient a-Si:H based solar cells. Despite the complexities in both the phenomena as well as the solar cells, progress has been made in both the scientific and technological arenas. This paper briefly reviews primarily studies on the characterization and reduction of the metastable changes in materials and the correlation of these changes with those in efficient solar cells. It will discuss the impact of studies on materials as well as the continuous advances made with “engineering” of solar cell structures on their improved stabilized performance.

Recent Advances in A-Si Solar Cell Technology in Japan

1986 ◽  
Vol 70 ◽  
Author(s):  
Y. Kuwano
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Single Junction ◽  
Si Solar Cell ◽  
Si Solar Cells ◽  
Recent Advances ◽  
Cell Structures ◽  
Cell Stability ◽  
Terminal Structure ◽  
Conversion Efficiencies

ABSTRACTRecent advances in a-Si solar cells in Japan are reviewed. Improvements in single-junction and multi-junction solar cells are described in three main points, namely, fabrication methods, materials, and cell structures. Recently, a conversion efficiency of 11.7% was obtained for a single-junction structure. For an a-Si/poly-Si stacked structure and an a-Si/(CdS/CdTe) 4 terminal structure, conversion efficiencies of more than 13% were achieved.Then recent advances in the prevention of the light induced degradation of a-Si solar cells is mentioned. Several methods which can improve the a-Si solar cell stability are described.Finally, the present status of the industrialization of a-Si solar cells and some of the latest applications are described together with their propects.

scholarly journals Study and Analytical Modeling of the Influence of Technological and Geometric Parameters on the Performance of Ga0:67In0:33P=GaAs=Ga0:70In0:30As Tri-junction Photovoltaic Solar Cells

2020 ◽  
pp. 66-78
Author(s):  
N. Ndorere ◽  
B. Kounouhewa ◽  
M.B. Agbomahena
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Geometric Parameters ◽  
Cell Structures ◽  
In Doping ◽  
Wide Range ◽  
Proportional Increase ◽  
The One ◽  
Photovoltaic Solar Cells

In the context of global energy consumption, the production of photovoltaic solar energy remains very low. One solution to this problem is to use multi-junction solar cells with high efficiency. Efforts are being made to increase the efficiency of solar cells and reduce their cost of production. In order to optimize the performance of multi-junction solar cells, this paper presents an analytical model allowing to study and model the influence of technological and geometric parameters on the performance of tri-junction solar cells Ga0:67In0:33P=GaAs=Ga0:70In0:30As. These parameters are the thickness, doping and Gap energy of the three sub-cells making up the tri-junction solar structure. The thicknesses and doping of the emitters (bases) of the sub-cells are varied and chosen in order to optimize the efficiency of the Trijunction Solar Cell (TJSC) Ga0:67In0:33P=GaAs=Ga0:70In0:30As. The one hand, the base doping (emitter) is selected so as to minimize the dark current and the other hand,to reduce the resistive losses in this region. As for the thickness, it is chosen so as to minimize the recombination phenomena. The simulation results show that for a given thickness, the sub-cell efficiencies have maximums which evolve with the increase in doping. If the doping of the base (or emitter) of the sub-cells increases, there follows a proportional increase in the efficiency. In addition, when the optimal doping and thickness of the bases (or emitters) are reached, above these, they can vary over a wide range without considerably modifying the efficiency of the solar cell. This point about the tolerance ranges is very important for the practical realization of Photovoltaic solar cell structures. These results also show that the optimal performance of the Tri-junction Solar Cell are obtained for the relatively low thicknesses of the bases (or emitters) (100nm-700nm) with high doping values(Nb = 8e + 18cm

Kinetics of Light Induced Changes in Protocrystalline Thin Film Materials and Solar Cells

2000 ◽  
Vol 609 ◽  
Author(s):  
Randy Koval ◽  
Xinwei Niu ◽  
Joshua Pearce ◽  
Lihong Jiao ◽  
Gautam Ganguly ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cells ◽  
Solar Cell ◽  
Degradation Kinetics ◽  
Cell Structures ◽  
The Many ◽  
Induced Changes ◽  
Charged Defects ◽  
Kinetics Of

ABSTRACTStudies have been carried out on the kinetics of light induced changes in thin films and solar cells fabricated in different laboratories. Unlike the many studies on undiluted a-Si:H films the kinetics reported here are for 1 sun illuminations carried out to the degraded steady state (DSS). The light induced changes at temperatures from 25 to 100°C were characterized with electron mobility lifetime products and subgap absorption in films and fill factors in solar cells. The significant changes in the degradation kinetics that occur in these materials in this t mperature range have further confirmed the importance of charged defects, not only in the annealed state, but also in the degraded steady states. Results are also presented on corresponding solar cell structures, which also indicate that defects other than neutral dangling bonds have to be taken into account if any meaningful evaluation is to be made of their solar cell properties.

Conventional polymer solar cells with power conversion efficiencies increased to >9% by a combination of methanol treatment and an anionic conjugated polyelectrolyte interface layer

RSC Advances ◽  
2014 ◽  
Vol 4 (92) ◽  
pp. 50988-50992 ◽  
Author(s):  
Tao Yuan ◽  
Dong Yang ◽  
Xiaoguang Zhu ◽  
Lingyu Zhou ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Thin Layer ◽  
Polymer Solar Cell ◽  
Polymer Solar Cells ◽  
Power Conversion ◽  
Interface Layer ◽  
Conjugated Polyelectrolyte ◽  
Methanol Treatment ◽  
Conversion Efficiencies

The power conversion efficiency of a PTB7:PC71BM polymer solar cell was improved up to 9.1% by a combination of methanol treatment followed by conjugation of a water- or alcohol-soluble polyelectrolyte thin layer.

scholarly journals Alternative electrodes for HTMs and noble-metal-free perovskite solar cells: 2D MXenes electrodes

RSC Advances ◽  
2019 ◽  
Vol 9 (59) ◽  
pp. 34152-34157 ◽  
Author(s):  
Junmei Cao ◽  
Fanning Meng ◽  
Liguo Gao ◽  
Shuzhang Yang ◽  
Yeling Yan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Noble Metal ◽  
Counter Electrode ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Perovskite Solar Cell ◽  
Metal Free ◽  
Conversion Efficiencies

The 2D Mxene material was successfully used as the counter electrode of the perovskite solar cell and achieved power conversion efficiencies of 13.84%.

Enhancement of photovoltaic properties of CH3NH3PbBr3 heterojunction solar cells by modifying mesoporous TiO2 surfaces with carboxyl groups

2015 ◽  
Vol 3 (17) ◽  
pp. 9264-9270 ◽  
Author(s):  
Hyun Bin Kim ◽  
Iseul Im ◽  
Yeomin Yoon ◽  
Sang Do Sung ◽  
Eunji Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Mesoporous Tio2 ◽  
Heterojunction Solar Cell ◽  
Carboxyl Groups ◽  
Photovoltaic Properties ◽  
Heterojunction Solar Cells ◽  
Light Absorber

In a novel heterojunction solar cell employing CH3NH3PbBr3 (MAPbBr3) as the light absorber, the introduction of a carboxylate monolayer on the mesoporous TiO2 surfaces significantly enhances JSC as well as VOC.

Theoretical Investigations of Polymer Based Solar Cells

2004 ◽  
Vol 822 ◽  
Author(s):  
Robert S. Echols ◽  
Chris E. France
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Band Gap ◽  
Polymer Blend ◽  
Bulk Heterojunction ◽  
Power Conversion ◽  
Normal Incidence ◽  
Open Circuit ◽  
Action Spectra ◽  
Conversion Efficiencies

AbstractWe investigate the behavior of a polymer blend (M3EH-PPV:CN-ether-PPV) bulk heterojunction solar cell using a numeric model that self-consistently solves Poisson's equation and the charge continuity equation while incorporating electric field dependent mobilities. We obtain good quantitative agreement with present experimental data for J-V curves and photocurrent action spectra. To reproduce experimental photocurrent action spectra, our model predicts 36% exciton dissociation efficiencies in the bulk of the polymer. We also study the limiting conditions of polymer solar cell development by simulating an ideal solar cell using an AM1.5 global spectrum and assuming all absorbed photons hitting a M3EH-PPV:CN-ether-PPV polymer blend (band gap ∼2.0 eV) based solar cell at normal incidence contribute to current. If such a solar cell has 100 nm length, open circuit voltage=0.6 V and 50% fill factor, then the maximum theoretical power conversion efficiency is ηp=5.6%. A similar analysis for a M3EH-PPV:PCBM bulk heterojunction cell yields, ηp=3.5%. These results further highlight the need to develop smaller band gap materials and help explain why the best polymer based solar cells have power conversion efficiencies that remain stuck at about 3%. Our model is used to investigate the important increase in power conversion efficiencies we can expect as lower band gap polymers become available.

Investigation of photovoltaic properties of dye-sensitized solar cells based on azo dyes contain various anchoring groups

2019 ◽  
Vol 48 (6) ◽  
pp. 481-486 ◽  
Author(s):  
Mozhgan Hosseinnezhad ◽  
Hanieh Shaki
Keyword(s):  
Solar Cells ◽  
Substituent Effect ◽  
Organic Dyes ◽  
Dye Sensitized Solar Cells ◽  
Photovoltaic Properties ◽  
Content Type ◽  
Dye Sensitized ◽  
Anchoring Groups ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

Purpose The purpose of this paper is to study the substituent effect in dye-sensitized solar cells’ (DSSCs) performance. For this end, three new metal organic dyes with DPA structure were synthesized. For investigation of the substituent effect, two different anchoring groups, namely, 1,3-dioxo-1Hbenz[de]isoquinolin-2(3H)-yl)benzenesulfonamides and 1,8-naphthalimide, were used. Design/methodology/approach Three organic dyes based on azo were selected, which contain various electron donor groups. Absorption properties of purified dyes were studied in solution and on photoelectrode (TiO2 and ZnO) substrate. DSSCs were prepared to determine the photovoltaic performance of each photosensitizer. Findings The results showed that all organic dyes form J-aggregation on the photoanode substrate. Cyclic voltammetry results for all organic dyes ensured an energetically permissible and thermodynamically favorable charge transfer throughout the continuous cycle of photo-electric conversion. The results illustrate conversion efficiencies of cells based on solution Dyes 1, 2 and 3 and TiO2 as 3.44, 4.71 and 4.82 per cent, respectively. The conversion efficiencies of cells based on solution Dye 1, 2 and 3 and ZnO are 3.21, 4.09 and 4.14 per cent, respectively. Practical implications In this study, the development of effect of assembling materials, offering improved photovoltaic properties. Social implications Organic dye attracts more and more attention because of its low-cost, facile route synthesis and less-hazardous properties. Originality/value To the best of the authors’ knowledge, the effect of anchoring agent and nanostructure on DSSCs performance was investigated for the first time.

scholarly journals Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

2016 ◽  
Vol 12 ◽  
pp. 1459-1466 ◽  
Author(s):  
Hideaki Komiyama ◽  
Chihaya Adachi ◽  
Takuma Yasuda
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Fullerene Derivative ◽  
Conjugated Oligomers ◽  
Visible Absorption ◽  
Photovoltaic Properties ◽  
Wide Range ◽  
Visible Wavelengths

Solution-processable star-shaped and linear π-conjugated oligomers consisting of an electron-donating tetrathienoanthracene (TTA) core and electron-accepting diketopyrrolopyrrole (DPP) arms, namely, TTA-DPP4 and TTA-DPP2, were designed and synthesized. Based on density functional theory calculations, the star-shaped TTA-DPP4 has a larger oscillator strength than the linear TTA-DPP2, and consequently, better photoabsorption property over a wide range of visible wavelengths. The photovoltaic properties of organic solar cells based on TTA-DPP4 and TTA-DPP2 with a fullerene derivative were evaluated by varying the thickness of the bulk heterojunction active layer. As a result of the enhanced visible absorption properties of the star-shaped π-conjugated structure, better photovoltaic performances were obtained with relatively thin active layers (40–60 nm).

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