Metamorphic GaInP-GaInAs Layers for Photovoltaic Applications

2004 ◽  
Vol 836 ◽  
Author(s):  
A. W. Bett ◽  
C. Baur ◽  
F. Dimroth ◽  
J. Schöne
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Triple Junction ◽  
Cell Structure ◽  
X Ray Diffraction ◽  
Solar Cell Performance ◽  
Transmission Electron ◽  
Layer Structures ◽  
Buffer Material ◽  
Metal Organic

ABSTRACTGaxIn1−xAs and GayIn1−yP layers were grown lattice mismatched to GaAs and Ge by low-pressure metal organic vapor phase epitaxy (LP-MOPVE). These materials are very promising for further increasing the efficiency of monolithic triple-junction solar cells. Different buffer layer structures were realized. Transmission electron microscopy and x-ray diffraction analysis were used to characterize the quality of the crystal. Both linear and step-graded buffers in GaxIn1−xAs were successfully used under an active solar cell structure. GayIn1−yP as buffer material showed a worse performance. Excellent solar cell performance was achieved for lattice mismatched single-, dual- and triple-junction solar cells.

Amorphous Silicon Alloy Materials and Solar Cells Near the Threshold of Microcrystallinity

1999 ◽  
Vol 557 ◽  
Author(s):  
J. Yang ◽  
S. Guha
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Triple Junction ◽  
High Efficiency ◽  
Spectral Response ◽  
High Quality ◽  
Silicon Alloys ◽  
Solar Cell Performance ◽  
Hydrogen Dilution

AbstractOne of the most effective techniques used to obtain high quality amorphous silicon alloys is the use of hydrogen dilution during film growth. The resultant material exhibits a more ordered microstructure and gives rise to high efficiency solar cells. As the hydrogen dilution increases, however, a threshold is reached, beyond which microcrystallites begin to form rapidly. In this paper, we review some of the interesting features associated with the thin film materials obtained from various hydrogen dilutions. They include the observation of linear-like objects in the TEM micrograph, a shift of the principal Si TO band in the Raman spectrum, a sharp, low temperature peak in the H2 evolution spectrum, a shift of the wagging mode in the IR spectrum, and a narrowing of the Si (111) peak in the X-ray diffraction pattern. These spectroscopic tools have allowed us to optimize deposition conditions to near the threshold of microcrystallinity and obtain desired high quality materials. Incorporation of the improved materials into device configuration has significantly enhanced the solar cell performance. Using a spectral-splitting, triple-junction configuration, the spectral response of a typical high efficiency device spans from below 350 nm to beyond 950 nm with a peak quantum efficiency exceeding 90%; the triple stack generates a photocurrent of 27 mA/cm2. This paper describes the effect of the improved materials on various solar cell structures, including a 13% active-area, stable triple-junction device.

Analysis of Strain Compensation in Quantum Dot Embedded GaAs Solar Cells

2007 ◽  
Vol 1031 ◽  
Author(s):  
Christopher Bailey ◽  
Cory Cress ◽  
Ryne Raffaelle ◽  
Seth Hubbard ◽  
William Maurer ◽  
...  
Keyword(s):  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
X Ray Diffraction ◽  
Solar Cell Performance ◽  
X Ray ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Strain Compensation

AbstractThe effects of strain within stacked layers of InAs quantum dots (QDs) were investigated. InAs QD test structures with and without strain compensation (SC) were analyzed using atomic force microscopy, transmission electron microscopy, and X-ray diffraction. The affects of strain compensation on test structure morphology and on GaAs-based QD solar cell performance was studied as a function of the thickness of the SC layer. X-ray diffraction analysis of the QD embedded test structures reveals a relationship between the SC thickness and the observed crystalline quality. Air mass zero illuminated current vs. voltage data and spectral responsivity measurements were used for the solar cell comparison. When SC is employed, QD insertion shows a lower open circuit voltage, in reference to a baseline device without QDs, but leads to an enhancement in the short circuit current of the device.

scholarly journals Passivation of InP solar cells using large area hexagonal-BN layers

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Vidur Raj ◽  
Dipankar Chugh ◽  
Lachlan E. Black ◽  
M. M. Shehata ◽  
Li Li ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Surface Passivation ◽  
Defect Density ◽  
Hexagonal Boron Nitride ◽  
Cell Structure ◽  
Chemical Vapor ◽  
Large Area ◽  
Solar Cell Performance ◽  
Passivation Layers

AbstractSurface passivation is crucial for many high-performance solid-state devices, especially solar cells. It has been proposed that 2D hexagonal boron nitride (hBN) films can provide near-ideal passivation due to their wide bandgap, lack of dangling bonds, high dielectric constant, and easy transferability to a range of substrates without disturbing their bulk properties. However, so far, the passivation of hBN has been studied for small areas, mainly because of its small sizes. Here, we report the passivation characteristics of wafer-scale, few monolayers thick, hBN grown by metalorganic chemical vapor deposition. Using a recently reported ITO/i-InP/p+-InP solar cell structure, we show a significant improvement in solar cell performance utilizing a few monolayers of hBN as the passivation layer. Interface defect density (at the hBN/i-InP) calculated using C–V measurement was 2 × 1012 eV−1cm−2 and was found comparable to several previously reported passivation layers. Thus, hBN may, in the future, be a possible candidate to achieve high-quality passivation. hBN-based passivation layers can mainly be useful in cases where the growth of lattice-matched passivation layers is complicated, as in the case of thin-film vapor–liquid–solid and close-spaced vapor transport-based III–V semiconductor growth techniques.

scholarly journals Self-doped carrier as a performance limiting factor of perovskite solar cells: study on tandem-junction cells with SCAPS

2021 ◽  
Vol 24 (1) ◽  
pp. 81
Author(s):  
Md. Sazzadur Rahman ◽  
Md. Samiur Rahman ◽  
Al Jaber ◽  
Suman Miah
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Carrier Concentration ◽  
Doping Concentration ◽  
Collection Efficiency ◽  
Cell Structure ◽  
Perovskite Solar Cells ◽  
The Self ◽  
Limiting Factor ◽  
Solar Cell Performance

<p>Doping concentration of the absorber layer plays a vital role in the performance of perovskite solar cells, because not only it has a direct impact on the collection efficiency of the photo generated carriers, but it can also be considered as an indicator of the film quality and aging process for so-called self-doped (unintentionally doped) perovskite absorbers, where the carriers are induced from structural imperfections. To observe its influence on the efficiency of perovskite solar cell, a two-junction solar cell structure MAPbBr3/MAPbI3 is analyzed in this study, employing a novel optoelectrical simulation approach with finite-difference time-domain (FDTD) analysis and solar cell capacitance simulation (SCAPS) program. It is found that, the efficiency of the tandem cell falls from ∼22% to ∼12% as front-cell absorber film degrades from single-crystal quality with low self-doped carrier concentration of the order of 1010cm−3 , to degraded film quality with very high carrier concentration of the order of 1018cm−3 . In contrast, the self-doped carrier concentration of the back-cell absorber illustrates less impact on the efficiency of the cell, especially for thicker front-cell absorber. Thus, this case study gives a simpler but novel insight into the long-term stability of the efficiency of high-performance perovskite solar cells establishing a link between the solar cell performance and the self-doped carrier concentration (doping concentration) of the absorber film.</p>

Correlation of Hydrogen Dilution Profiling to Material Structure and Device Performance of Hydrogenated Nanocrystalline Silicon Solar Cells

2008 ◽  
Vol 1066 ◽  
Author(s):  
Baojie Yan ◽  
Guozhen Yue ◽  
Yanfa Yan ◽  
Chun-Sheng Jiang ◽  
Charles W. Teplin ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Cell Structure ◽  
Nanocrystalline Silicon ◽  
Cell Performance ◽  
Solar Cell Performance ◽  
Seeding Layer ◽  
Single Junction ◽  
Junction Solar Cell ◽  
Hydrogen Dilution

ABSTRACTWe present a systematic study on the correlation of hydrogen dilution profiles to structural properties materials and solar cell performance in nc-Si:H solar cells. We deposited nc-Si:H single-junction solar cells using a modified very high frequency (VHF) glow discharge technique on stainless steel substrates with various profiles of hydrogen dilution in the gas mixture during deposition. The material properties were characterized using Raman spectroscopy, X-TEM, AFM, and C-AFM. The solar cell performance correlates well with the material structures. Three major conclusions are made based on the characterization results. First, the optimized nc-Si:H material does not show an incubation layer, indicating that the seeding layer is well optimized and works as per design. Second, the nanocrystalline evolution is well controlled by hydrogen dilution profiling in which the hydrogen dilution ratio is dynamically reduced during the intrinsic layer deposition. Third, the best nc-Si:H single-junction solar cell was made using a proper hydrogen dilution profile, which caused a nanocrystalline distribution close to uniform throughout the thickness, but with a slightly inverse nanocrystalline evolution. We have used the optimized hydrogen dilution profiling and improved the nc-Si:H solar cell performance significantly. As a result, we have achieved an initial active-area cell efficiency of 9.2% with a nc-Si:H single-junction structure, and 15.4% with an a-Si:H/a-SiGe:H/nc-Si:H triple-junction solar cell structure.

Doping Effect on Chloroindium Phthalocyanine (ClInPc)/C60 Solar Cells

2012 ◽  
Vol 1390 ◽  
Author(s):  
Weining Wang ◽  
Neal Armstrong
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Fermi Level ◽  
Cell Structure ◽  
Short Circuit ◽  
Level Shift ◽  
Semiconductor Interface ◽  
Solar Cell Performance ◽  
Fermi Level Shift ◽  
Inorganic Semiconductor

ABSTRACTFor inorganic semiconductor solar cells, controlled doping is important because it can cause Fermi level shift of the inorganic semiconductor and achieve ohmic contact at the metal-semiconductor interface. In this paper we show that doping can also be used to shift Fermi level in organic semiconductors and cause changes in solar cell performance. We have made chloroindium phthalocyanine (ClInPc)/C60 heterojunction solar cells, where tetrafluoro-teracyano-quinodimethane (F4-TCNQ) is used to dope ClInPc layer. Ultraviolet photoemission spectroscopy (UPS) is used to investigate the ITO/ClInPc interfaces. The result shows that doping causes a Fermi level shift at the ITO/ClInPc interface as it does for inorganic semiconductors. As the doping increases, dark saturation current J0 of the solar cell increases, while open-circuit voltage Voc, short-circuit current Jsc and fill factor decreases. As a result, the efficiency of the solar cell decreases as doping increases. More UPS studies on ClInPc (doped with F4TCNQ)/C60 junction are needed to correlate the energy band diagram of the whole solar cell structure with the J-V characteristics.

The Test System Design of Multi-Junction Solar Cell Spectral Response

2013 ◽  
Vol 706-708 ◽  
pp. 1094-1098
Author(s):  
Fang Bai ◽  
Ke Yuan Cheng ◽  
Shan Li
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Electrical Properties ◽  
Triple Junction ◽  
Spectral Response ◽  
Performance Testing ◽  
Demonstration Program ◽  
Excitation Light ◽  
Solar Cell Performance ◽  
Junction Solar Cell

The main topic is on doing research and testing methods and theories of the triple-junction solar cell and design its electrical performance test platform. Provide a theoretical basis and feasible experimental triple-junction solar cell performance testing. The electrical properties of the electrical properties of solar cells is the main consideration for its use as a power, a very important one is the spectral response curve of the test. Demonstration program and platform for the entire system, the P / N junction between the optical and electrical characteristics of multi-junction solar cells affect each other, related to the key issues, including: monochromatic excitation light source, optical bias, the theory and technology of electrical bias, weak signal detection. Important application prospects based multi-junction solar cells, its theoretical method and test device to become an important and innovative topic.

Optical Simulations of the Effects of Transparent Conducting Oxide Interface Layers on Amorphous Silicon Solar Cell Performance

2001 ◽  
Vol 664 ◽  
Author(s):  
Gelio M. Ferreira ◽  
Andre S. Ferlauto ◽  
Pablo I. Rovira ◽  
Chi Chen ◽  
Hien V. Nguyen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Cell Structure ◽  
Transparent Conducting Oxide ◽  
Oxide Interface ◽  
Solar Cell Performance ◽  
Beneficial Effects ◽  
Amorphous Silicon Solar Cell ◽  
Interface Layers

ABSTRACTSpectroscopic ellipsometry (SE) analysis of so-called “specular” (macroscopically smooth) and “textured” (macroscopically rough) thin film amorphous silicon (a-Si:H) based solar cell structures demonstrates the need to incorporate interface layers into the multilayer stack in order to simulate the observed Stokes vector of the specularly-reflected beam. In most cases, these layers can be attributed to microscopic roughness (e.g., at the SnO2/p-layer/i-layer interface in a-Si:H p-i-n solar cells), as verified by atomic force microscopy (AFM). In limited cases, the layers may include regions wherein chemical intermixing also occurs (e.g., at the ZnO/Ag interface in back-reflectors), particularly for overlying films prepared by sputtering. In spite of the clear evidence for the existence of interface layers, they have been neglected in previous simulations of the optical quantum efficiency (QE) of the solar cells. In this study, we incorporate the experimentally- observed characteristics of interface layers as input into optical models for the p-i-n solar cell structure. In this way, we demonstrate the beneficial effects of SnO2/p/i interface microroughness as an anti-reflector and the detrimental effects of the ZnO/Ag interlayer as a parasitic absorber.

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.

Optimisation of diketopyrrolopyrrole:fullerene solar cell performance through control of polymer molecular weight and thermal annealing

2014 ◽  
Vol 2 (45) ◽  
pp. 19282-19289 ◽  
Author(s):  
Zhenggang Huang ◽  
Elisa Collado Fregoso ◽  
Stoichko Dimitrov ◽  
Pabitra Shakya Tuladhar ◽  
Ying Woan Soon ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Solar Cells ◽  
Solar Cell ◽  
Thermal Annealing ◽  
Bulk Heterojunction ◽  
Cell Performance ◽  
Polymer Molecular Weight ◽  
Solar Cell Performance ◽  
Heterojunction Solar Cells ◽  
Bulk Heterojunction Solar Cells

The performance of bulk heterojunction solar cells based on a novel donor polymer DPP-TT-T was optimised by tuning molecular weight and thermal annealing.

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