Impact of thickness variation of the ZnO:Al window layer on optoelectronic properties of CIGSSe solar cells

2011 ◽  
Vol 1324 ◽  
Author(s):  
Jan Keller ◽  
Martin Knipper ◽  
Jürgen Parisi ◽  
Ingo Riedel ◽  
Thomas Dalibor ◽  
...  
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Window Layer ◽  
Process Time ◽  
Thickness Variation ◽  
Doping Density ◽  
Time Required

ABSTRACTWe studied the thickness variation of equally doped ZnO:Al films used as conductive window layer in Cu(In,Ga)(Se,S)2 (CIGSSe) thin film solar cells. The IV-characteristics of solar cells with window layer thickness of d1=200nm exhibit a strong enhancement of the short-circuit current density JSC (ΔJSC = 3mA/cm2) as compared to samples with module-like ZnO:Al-film thickness (d2=1200nm). Accordingly, the quantum efficiency reveals the spectral regimes where the JSC-gain occurs. Moreover, current-voltage measurements reveal that the cells with thicker ZnO:Al exhibit slightly decreased open circuit voltage VOC. This finding can be assigned to a decreased net-doping density NA, which appears to be introduced by additional heat flux during the longer process time required for deposition of thicker ZnO:Al films. However, the improved efficiency of solar cells with thinner window layer comes along with an increase of the series resistance (RS) by almost a factor of 2, which will have consequences for the series connection of elements in a module. XRD-diffractograms and SEM cross-section imaging suggest that the enhanced RS in cells with thin ZnO:Al is not exclusively related to the thickness but is also due to a reduced (002)-texture and an elongated lateral charge carrier pathway.

Solar Cells on Foreign Substrates Using Poly-Si Thin Films by Metal Induced Growth

2004 ◽  
Vol 808 ◽  
Author(s):  
Chunhai Ji ◽  
Wayne A. Anderson
Keyword(s):  
Solar Cells ◽  
Ion Implantation ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Doping Density ◽  
Charge Densities ◽  
Metal Induced Growth

ABSTRACTThe poly-Si film was deposited by using the metal-induced growth (MIG) method on tungsten substrates. By making Au/n-Si Schottky photo-diodes, doping density effect was studied by using three different doping level Si sputtering targets. Increasing the Si target resistivities from 0.02Ω-cm to 50Ω-cm, open-circuit-voltage (Voc) decreased from 0.22V to 0.14V while short-circuit-current density (Jsc) increased from 1.55mA/cm2 to 2.42mA/cm2. C-V results revealed a high charge density in the device, which may be due to the oxygen thermal donor effects. Using an oxygen filter for the sputtering gas effectively reduced the charge densities and increased the Jsc value. The p/n junction solar cells were fabricated by using ion implantation at 1013∼1014cm−2 dose and 100∼200keV. The cells with wider emitter layer by double-ion implantation gave higher Jsc and Voc values. Passivation of the Si film by using hydrogenation improved the Jsc, Voc and spectral response of the solar cells.

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

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.

scholarly journals Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4268
Author(s):  
Jessica de Wild ◽  
Gizem Birant ◽  
Guy Brammertz ◽  
Marc Meuris ◽  
Jef Poortmans ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Electron Microscopic ◽  
Current Increase ◽  
Time Resolved ◽  
Cigs Solar Cells

Ultrathin Cu(In,Ga)Se2 (CIGS) absorber layers of 550 nm were grown on Ag/AlOx stacks. The addition of the stack resulted in solar cells with improved fill factor, open circuit voltage and short circuit current density. The efficiency was increased from 7% to almost 12%. Photoluminescence (PL) and time resolved PL were improved, which was attributed to the passivating properties of AlOx. A current increase of almost 2 mA/cm2 was measured, due to increased light scattering and surface roughness. With time of flight—secondary ion mass spectroscopy, the elemental profiles were measured. It was found that the Ag is incorporated through the whole CIGS layer. Secondary electron microscopic images of the Mo back revealed residuals of the Ag/AlOx stack, which was confirmed by energy dispersive X-ray spectroscopy measurements. It is assumed to induce the increased surface roughness and scattering properties. At the front, large stains are visible for the cells with the Ag/AlOx back contact. An ammonia sulfide etching step was therefore applied on the bare absorber improving the efficiency further to 11.7%. It shows the potential of utilizing an Ag/AlOx stack at the back to improve both electrical and optical properties of ultrathin CIGS solar cells.

scholarly journals Effects of Different Doping Ratio of Cu Doped CdS on QDSCs Performance

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Xiaojun Zhu ◽  
Xiaoping Zou ◽  
Hongquan Zhou
Keyword(s):  
Solar Cells ◽  
Quantum Dot ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Photoelectric Conversion Efficiency ◽  
Photoelectric Conversion ◽  
Sensitized Solar Cells ◽  
Doping Ratio

We use the successive ionic layer adsorption and reaction (SILAR) method for the preparation of quantum dot sensitized solar cells, to improve the performance of solar cells by doping quantum dots. We tested the UV-Vis absorption spectrum of undoped CdS QDSCs and Cu doped CdS QDSCs with different doping ratios. The doping ratios of copper were 1 : 100, 1 : 500, and 1 : 1000, respectively. The experimental results show that, under the same SILAR cycle number, Cu doped CdS quantum dot sensitized solar cells have higher open circuit voltage, short circuit current density photoelectric conversion efficiency than undoped CdS quantum dots sensitized solar cells. Refinement of Cu doping ratio are 1 : 10, 1 : 100, 1 : 200, 1 : 500, and 1 : 1000. When the proportion of Cu and CdS is 1 : 10, all the parameters of the QDSCs reach the minimum value, and, with the decrease of the proportion, the short circuit current density, open circuit voltage, and the photoelectric conversion efficiency are all increased. When proportion is 1 : 500, all parameters reach the maximum values. While with further reduction of the doping ratio of Cu, the parameters of QDSCs have a decline tendency. The results showed that, in a certain range, the lower the doping ratio of Cu, the better the performance of quantum dot sensitized solar cell.

scholarly journals SCAPS Simulation on P3HT:Graphene Nanocomposites Based Bulk-Heterojunction Organic Solar Cells

2019 ◽  
Vol 9 (1) ◽  
pp. 28
Author(s):  
Nur Shakina Mohd Shariff ◽  
Puteri Sarah Mohamad Saad ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Fill Factor ◽  
Bulk Heterojunction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Simulation Software ◽  
Capacitance Voltage

There has been an increasing interest towards organic solar cells after the discovery of conjugated polymer and bulk-heterojunction concept. Eventhough organic solar cells are less expensive than inorganic solar cells but the power conversion energy is still considered low. The main objective of this research is to investigate the effect of the P3HT’s thickness and concentration towards the efficiency of the P3HT:Graphene solar cells. A simulation software that is specialize for photovoltaic called SCAPS is used in this research to simulate the effect on the solar cells. The solar cell’s structure will be drawn inside the simulation and the parameters for each layers is inserted. The result such as the open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), efficiency (η), capacitance-voltage (C-V) and capacitance-frequency (C-f) characteristic will be calculated by the software and all the results will be put into one graph.

scholarly journals Benzothiadiazole Based Cascade Material to Boost the Performance of Inverted Ternary Organic Solar Cells

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 450 ◽  
Author(s):  
Miron Krassas ◽  
Christos Polyzoidis ◽  
Pavlos Tzourmpakis ◽  
Dimitriοs M. Kosmidis ◽  
George Viskadouros ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Fused Ring ◽  
Electron Cascade ◽  
First Time

A conjugated, ladder-type multi-fused ring 4,7-dithienbenzothiadiazole:thiophene derivative, named as compound ‘T’, was for the first time incorporated, within the PTB7:PC71BM photoactive layer for inverted ternary organic solar cells (TOSCs) realization. The effective energy level offset caused by compound T between the polymeric donor and fullerene acceptor materials, as well as its resulting potential as electron cascade material contribute to an enhanced exciton dissociation, electron transfer facilitator and thus improved overall photovoltaic performance. The engineering optimization of the inverted TOSC, ITO/PFN/PTB7:Compound T(5% v/v):PC71BM/MoO3/Al, resulted in an overall power conversion efficiency (PCE) of 8.34%, with a short-circuit current density (Jsc) of 16.75 mA cm−2, open-circuit voltage (Voc) of 0.74 V and a fill factor (FF) of 68.1%, under AM1.5G illumination. This photovoltaic performance was improved by approximately 12% with respect to the control binary device.

High-efficiency CIGS solar cell by optimization of doping concentration, thickness and energy band gap

2019 ◽  
Vol 34 (04) ◽  
pp. 2050053
Author(s):  
Fatemeh Ghavami ◽  
Alireza Salehi
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
High Efficiency ◽  
Cell Structure ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Absorber Layer ◽  
Window Layer

In this paper, the performance of copper-indium-gallium-diselenide Cu(In,Ga)Se2 solar cell, with ZnO window layer, ZnSe buffer layer, CIGS absorber layer and InGaP reflector layer was studied. The study was performed using the TCAD Silvaco simulator. The effects of grading the band gap of CIGS absorber layer, the various thicknesses and doping concentrations of different layers have been investigated. By optimizing the solar cell structure, we have obtained a maximum open circuit voltage of 0.91901 V, a short circuit current density of 39.89910 mA/cm2, a fill factor (FF) of 86.67040% and an efficiency of 31.78% which is much higher than the values for similar CIGS solar cells reported so far.

Preparation of the Three Main Layers of CdS/CdTe Thin Film Solar Cells Using a Single Vacuum System

2011 ◽  
Vol 378-379 ◽  
pp. 601-605 ◽  
Author(s):  
Saleh N. Alamri ◽  
M. S. Benghanem ◽  
A. A. Joraid
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Fused Silica ◽  
Vacuum System ◽  
Cdte Thin Film

This study investigates the preparation of the three main layers of a CdS/CdTe thin film solar cell using a single vacuum system. A Close Space Sublimation System was constructed to deposit CdS, CdTe and CdCl2 solar cell layers. Two hot plates were used to heat the source and the substrate. Three fused silica melting dishes were used as containers for the sources. The properties of the deposited CdS and CdTe films were determined via Atomic force microscopy, scanning electron microscopy, X-ray diffraction and optical transmission spectroscopy. An J-V characterization of the fabricated CdS/CdTe solar cells was performed under solar radiation. The short-circuit current density, Jsc, the open-circuit voltage, Voc, fill factor, FF and conversion efficiency, η, were measured and yielded values of 27 mA/cm2, 0.619 V, 58% and 9.8%, respectively.

RELIABILITY STUDIES OF P3HT: PCBM ORGANIC SOLAR CELLS FABRICATED WITH CALCIUM–ALUMINUM AND LITHIUM FLUORIDE–ALUMINIUM CATHODES

2011 ◽  
Vol 10 (04n05) ◽  
pp. 803-807
Author(s):  
T. S. KRISHNAN ◽  
S. SUNDAR KUMAR IYER
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Continuous Illumination ◽  
Stress Tests ◽  
Ambient Conditions ◽  
Over Time

This work addresses the shelf life characteristics of P3HT: PCBM blend based organic solar cells (OSC) fabricated with Ca–Al and LiF–Al cathodes. Some of these devices are encapsulated in nitrogen ambient and some in room ambient. Device electrical characteristics are studied under both dark and light. In the analysis under dark ambient conditions, the degradation in peak dark current is monitored over time (in days) and an empirical model is postulated for the degradation based on statistical curve fitting techniques. In the analysis under light, degradation of parameters such as fill factor (FF), open circuit voltage (V oc ) and short circuit current density (J sc ) is monitored over time in these devices (for different cathodes and different ambients) and the results are analyzed and compared. Also, accelerated stress tests are conducted wherein the devices are subjected to continuous illumination for a period of 1.5 h under two different intensities (0.76 sun and 1 sun) and again, the results are analyzed and compared. A model is fitted to the observed degradation in normalized J sc and the degradation constants (k deg ) are obtained. It is seen that the devices fabricated with cathode as LiF–Al and being encapsulated in nitrogen ambient provide the best performance over time.

CONTRIBUTION OF n-TYPE AMORPHOUS CARBON ON THE FABRICATION OF n-C:P/p-Si SOLAR CELLS

2004 ◽  
Vol 11 (06) ◽  
pp. 569-575 ◽  
Author(s):  
M. RUSOP ◽  
T. SOGA ◽  
T. JIMBO ◽  
M. UMENO
Keyword(s):  
Solar Cells ◽  
Photoelectron Spectroscopy ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Energy Conversion Efficiency ◽  
Carbon Films ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
P Content ◽  
Phosphorus Doped

The phosphorus doped n -type ( n - C : P ) carbon films and fabrication of n - C : P / p - Si heterojunction solid-state solar cells by pulsed laser deposition (PLD) technique at room temperature using graphite target have been studied. The P atoms incorporated in the films were determined by X-ray photoelectron spectroscopy (XPS) to be in the range of 0.22–1.77 atomic percentages. The cells performances have been given in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm2, 25°C). The open circuit voltage ( V oc ) and short circuit current density ( J sc ) for the cells are observed to vary from 215 to 265 mV and from 7.5 to 10.5 mA/cm2, respectively. The cell fabricated using the target with the amount of P by 7 weight percentages (Pwt%) shows the highest energy conversion efficiency, η=1.14% and fill factor, FF =41%. In this paper, the dependence of P content on the electrical and optical properties of the deposited n - C : P films and the photovoltaic characteristic of the n - C : P / p - Si cells are reported.

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