Implementation of Highly Resistive Emitter Solar Cells in a Production Environment using an Inline Doping System

2011 ◽  
Vol 178-179 ◽  
pp. 441-445
Author(s):  
Wolfgang Wille ◽  
Ralph Rothemund ◽  
Gerald Meinhardt ◽  
Wolfgang Jantsch
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Surface Concentration ◽  
Open Circuit ◽  
Doping Profile ◽  
Process Conditions ◽  
Production Environment ◽  
Cell Efficiency ◽  
Set Up

Instead of selective emitter technology we investigate an alternative way to optimize contact formation and increased blue responsivity of highly resistive emitter solar cells using screen print technology for the deposition of the frontside metallization grid. We show with the aid of an inline doping/diffusion set-up at Blue Chip Energy that tuning the emitter doping profile is an alternative way to reduce the effect of Auger recombination in the spectral range from 300 nm to 600 nm. By properly choosing the process conditions we were able to minimize the detrimental effect of the low surface concentration of the dopant on the contact resistance. Due to improved blue light responsivity a significant gain in short circuit current Jsc was achieved. This and a reduced reverse saturation current I00E yielded a higher open circuit voltage VOC and an increase of cell efficiency from 17.6 %-avg to more than 17.9 %-avg.

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.

Simulation of Symmetrically Doped Silicon Nanowire Solar Cells

2011 ◽  
Vol 1322 ◽  
Author(s):  
Felix Voigt ◽  
Thomas Stelzner ◽  
Silke H. Christiansen
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Silicon Nanowire ◽  
Short Circuit Current ◽  
Cylindrical Symmetry ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Back Surface ◽  
Cell Efficiency ◽  
P Type

ABSTRACTSilicon nanowire solar cells were simulated using the Silvaco TCAD software kit. For optimization of speed the simulations were performed in cylinder coordinates with cylindrical symmetry. Symmetric doping was assumed with a dopant density of 1018 cm-3 in the p-type core and inside the n-type shell. In the implementation a cathode contact was wrapped around the semiconductor nanorod and an anode was assumed at the bottom of the rod. Optimization of cell efficiency was performed with regard to the rod radius and the rod length. In both optimization processes clear maxima in efficiency were visible, resulting in an optimal radius of 66 nm with the pn junction at 43.5 nm and an optimal rod length of about 48 μm. The maximum of efficiency with respect to the rod radius is due to a decrease of short-circuit current density (Jsc) and an increase of open-circuit voltage (Uoc) with radius, while the maximum with respect to the rod length is explained by the combination of an increase of Jsc and a decrease of Uoc. Fill factors stay rather constant at values between 0.6 and 0.8. Further, the influence of a back surface field (BSF) layer was surveyed in simulations. Positioning the BSF next to the cathode contact considerably improved cell efficiency. In addition, simulations with a cathode contact on top of the nanowire structure were undertaken. No severe deterioration of cell performance with increasing radius was observed so far in this configuration. Hence, nanorods with much larger radii can be used for solar cells using this contact scheme. In comparison to simulations with wrapped cathode contacts, Jsc and Uoc and therefore efficiency is considerably improved.

Lock-in Thermography-Based Local Efficiency Analysis of Solar Cells

2012 ◽  
Author(s):  
Otwin Breitenstein
Keyword(s):  
Solar Cells ◽  
Short Circuit ◽  
Efficiency Analysis ◽  
Open Circuit ◽  
Local Defect ◽  
Whole Cell ◽  
Local Efficiency ◽  
Cell Efficiency ◽  
Lock In ◽  
Efficiency Data

Abstract The electronic properties of solar cells, particularly multicrystalline silicon-based ones, are distributed spatially inhomogeneous, where regions of poor quality may degrade the performance of the whole cell. These inhomogeneities mostly affect the dark current-voltage (I-V) characteristic, which decisively affects the efficiency. Since the grid distributes the local voltage homogeneously across the cell and leads to lateral balancing currents, local light beam-induced current methods alone cannot be used to image local cell efficiency parameters. Lock-in thermography (LIT) is the method of choice for imaging inhomogeneities of the dark I-V characteristic. This contribution introduces a novel method for evaluating a number of LIT images taken at different applied biases. By pixel-wise fitting the data to a two diode model and taking into account local series resistance and short circuit current density data, realistically simulated images of the other cell efficiency parameters (open circuit voltage, fill factor, and efficiency) are obtained. Moreover, simulated local and global dark and illuminated I-V characteristics are obtained, also for various illumination intensities. These local efficiency data are expectation values, which would hold if a homogeneous solar cell had the properties of the selected region of the inhomogeneous cell. Alternatively, also local efficiency data holding for the cell working at its own maximum power point may be generated. The amount of degradation of different cell efficiency parameters in some local defect positions is an indication how dangerous these defects are for degrading this parameter of the whole cell. The method allows to virtually 'cut out' certain defects for checking their influence on the global characteristics. Thus, by applying this method, a detailed local efficiency analysis of locally inhomogeneous solar cells is possible. It can be reliably predicted how a cell would improve if certain defects could be avoided. This method is implemented in a software code, which is available.

scholarly journals GaInP/GaAs/poly-Si Multi-Junction Solar Cells by in Metal Balls Bonding

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 726
Author(s):  
Ray-Hua Horng ◽  
Yu-Cheng Kao ◽  
Apoorva Sood ◽  
Po-Liang Liu ◽  
Wei-Cheng Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Low Temperature ◽  
Triple Junction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Metal Line ◽  
Solar Simulator ◽  
Junction Solar Cell

In this study, a mechanical stacking technique has been used to bond together the GaInP/GaAs and poly-silicon (Si) solar wafers. A GaInP/GaAs/poly-Si triple-junction solar cell has mechanically stacked using a low-temperature bonding process which involves micro metal In balls on a metal line using a high-optical-transmission spin-coated glue material. Current–voltage measurements of the GaInP/GaAs/poly-Si triple-junction solar cells have carried out at room temperature both in the dark and under 1 sun with 100 mW/cm2 power density using a solar simulator. The GaInP/GaAs/poly-Si triple-junction solar cell has reached an efficiency of 24.5% with an open-circuit voltage of 2.68 V, a short-circuit current density of 12.39 mA/cm2, and a fill-factor of 73.8%. This study demonstrates a great potential for the low-temperature micro-metal-ball mechanical stacking technique to achieve high conversion efficiency for solar cells with three or more junctions.

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 Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics

2018 ◽  
Vol 9 ◽  
pp. 1802-1808 ◽  
Author(s):  
Katherine Atamanuk ◽  
Justin Luria ◽  
Bryan D Huey
Keyword(s):  
Solar Cells ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Three Dimensional ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Photovoltaic Properties ◽  
Order Of Magnitude ◽  
Individual Grains

The nanoscale optoelectronic properties of materials can be especially important for polycrystalline photovoltaics including many sensor and solar cell designs. For thin film solar cells such as CdTe, the open-circuit voltage and short-circuit current are especially critical performance indicators, often varying between and even within individual grains. A new method for directly mapping the open-circuit voltage leverages photo-conducting AFM, along with an additional proportional-integral-derivative feedback loop configured to maintain open-circuit conditions while scanning. Alternating with short-circuit current mapping efficiently provides complementary insight into the highly microstructurally sensitive local and ensemble photovoltaic performance. Furthermore, direct open-circuit voltage mapping is compatible with tomographic AFM, which additionally leverages gradual nanoscale milling by the AFM probe essentially for serial sectioning. The two-dimensional and three-dimensional results for CdTe solar cells during in situ illumination reveal local to mesoscale contributions to PV performance based on the order of magnitude variations in photovoltaic properties with distinct grains, at grain boundaries, and for sub-granular planar defects.

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.

Study of Photoelectrochemical Solar Cell Using WSe2 Crystal

2013 ◽  
Vol 665 ◽  
pp. 330-335 ◽  
Author(s):  
Ripal Parmar ◽  
Dipak Sahay ◽  
R.J. Pathak ◽  
R.K. Shah
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrical Energy ◽  
Open Circuit ◽  
Cell Parameters ◽  
Photoelectrochemical Solar Cell ◽  
Photoelectrochemical Solar Cells

The solar cells have been used as most promising device to convert light energy into electrical energy. In this paper authors have attempted to fabricate Photoelectrochemical solar cell with semiconductor electrode using TMDCs. The Photoelectrochemical solar cells are the solar cells which convert the solar energy into electrical energy. The photoelectrochemical cells are clean and inexhaustible sources of energy. The photoelectrochemical solar cells are fabricated using WSe2crystal and electrolyte solution of 0.025M I2, 0.5M NaI, 0.5M Na2SO4. Here the WSe2crystals were grown by direct vapour transport technique. In our investigations the solar cell parameters like short circuit current (Isc) and Open circuit voltage (Voc) were measured and from that Fill factor (F.F.) and photoconversion efficiency (η) are investigated. The results obtained shows that the value of efficiency and fill factor of solar cell varies with the illumination intensities.

Solar Cell Contacts Using Nano-Sized Dispersions

1999 ◽  
Vol 581 ◽  
Author(s):  
Doug Schulz ◽  
R. Ribelin ◽  
X. Wu ◽  
K.M. Jones ◽  
R.J. Matson ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spray Deposition ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Cdte Layer ◽  
Open Circuit ◽  
Alloy Formation ◽  
Current Densities ◽  
P Type ◽  
Open Circuit Voltages

ABSTRACTNano-sized dispersions have been employed as precursor inks for the spray deposition of contacts to both Si and CdTe materials. In the case of Si, nano-sized Al particles (nano-Al) were dispersed and spray deposited onto p-type Si. Annealing above the eutectic temperature causes alloy formation yielding a p+ layer with p ∼ 10−4 Ω•cm. For CdTe, nano-sized Te particles (nano-Te) were dispersed and sprayed onto CdTe/CdS/SnO2/glass heterostructures. Contact to the CdTe layer occurred during a 30 min anneal in He (T = 215 to 255 °C). These solar cells were finished by spin-coating the Te layer with Ag paint and subsequently annealing in air (100 °C / 1 h). This approach produces solar cells with open circuit voltages (Voc) from 720 to 800 mV, short circuit current densities (Jsc) from 18 to 20 mA/cm2 and efficiencies up to 10.3%. The performance of these cells was similar to those produced using the standard NREL contact.

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.

Sign in / Sign up

Export Citation Format

Share Document