Search results for "photovoltaic"
showing 10 items of 646 documents
Semitransparent Perovskite Solar Cells for Building Integration and Tandem Photovoltaics: Design Strategies and Challenges
2021
Over the past decade, halide perovskite systems have captured widespread attention among researchers since their exceptional photovoltaic (PV) performance was disclosed. The unique combination of optoelectronic properties and solution processability shown by these materials has enabled perovskite solar cells (PSCs) to reach efficiencies higher than 25% at low fabrication costs. Moreover, PSCs display enormous potential for modern unconventional PV applications, since they can be made lightweight, semitransparent (ST), and/or flexible by means of appropriate design strategies. In particular, by enabling transparency and high efficiency simultaneously, ST-PSCs hold great promise for future ve…
Laser irradiation of ZnO:Al/Ag/ZnO:Al multilayers for electrical isolation in thin film photovoltaics
2013
Laser irradiation of ZnO:Al/Ag/ZnO:Al transparent contacts is investigated for segmentation purposes. The quality of the irradiated areas has been experimentally evaluated by separation resistance measurements, and the results are complemented with a thermal model used for numerical simulations of the laser process. The presence of the Ag interlayer plays two key effects on the laser scribing process by increasing the maximum temperature reached in the structure and accelerating the cool down process. These evidences can promote the use of ultra-thin ZnO:Al/ Ag/ZnO:Al electrode in large-area products, such as for solar modules. © 2013 Crupi et al.; licensee Springer.
Improvement of DSSC performance by voltage stress application
2016
Dye-sensitized solar cells (DSSCs) are promising third generation photovoltaic devices given their potential low cost and high efficiency. Some factors still affect DSSCs performance, such structure of electrodes, electrolyte compositions, nature of the sensitizers, power conversion efficiency, long-term stability, etc. In this work we discuss the effect of electrical stresses, which allow to improve DSSC performance. We have investigated the outcomes of forward and reverse DC bias stress as a function of time, voltage, and illumination level in the DSSCs sensitized with the N719, Ruthenium complex based dye. We demonstrate that all the major solar cell parameters, i.e., open circuit voltag…
Tunable Wide‐Bandgap Monohalide Perovskites
2020
Herein the mechanochemical synthesis of inorganic as well as hybrid organic-inorganic monohalide perovskites with tunable bandgaps is reported. It is shown that the bandgap bowing known for iodide mixed Sn-Pb perovskites is also present in the pure bromide analogous. This results in technologically very interesting materials with bandgaps in the range of 1.7-1.9 eV. Similar bandgap perovskites are typically achieved by mixing two halides that are prone to segregate over time. This limits the achievable open circuit voltage. For monohalide perovskites this problem is eliminated, making these materials especially promising wide bandgap absorbers for tandem solar cells. Perovskite Thin-film Ph…
Metal Chalcohalides: Next Generation Photovoltaic Materials?
2021
Metal chalcohalides have recently been highlighted as so-far overlooked semiconductors that could play an important role in the future of photovoltaics (PV). Indeed, the blooming field of emergent PV technologies is still in search for stable, efficient, and environmentally-friendly light-harvesting materials to be used either in single-junction solar cells or multijunction devices in combination with silicon or another absorbers. Under the broad terms of metal chalcohalides, there exists a plethora of semiconductor materials with different chemical, structural, and optoelectronic characteristics. While some have already been implemented in solar cells with power conversion efficiencies up …
FAPb0.5Sn0.5I3: A Narrow Bandgap Perovskite Synthesized through Evaporation Methods for Solar Cell Applications
2020
The tunability of the optoelectrical properties upon compositional modification is a key characteristic of metal halide perovskites. In particular, bandgaps narrower than those in conventional lead‐based perovskites are essential to achieve the theoretical efficiency limit of single‐absorber solar cells, as well as develop multijunction tandem devices. Herein, the solvent‐free vacuum deposition of a narrow bandgap perovskite based on tin-lead metal and formamidinium cation is reported. Pinhole‐free films with 1.28 eV bandgap are obtained by thermal codeposition of precursors. The optoelectrical quality of these films is demonstrated by their use in solar cells with a power conversion effici…
Low Temperature, Vacuum-Processed Bismuth Triiodide Solar Cells with Organic Small-Molecule Hole Transport Bilayer
2021
Herein, the preparation of fully vacuum-processed bismuth triiodide solar cells with low annealing temperature is reported. Planar n-i-p devices are prepared using a thin compact SnO2 layer as the electron extraction layer and an electron blocking/hole extraction bilayer consisting of an intrinsic and doped organic hole-transport molecule. Using this configuration, herein, higher fill-factors and overall power conversion efficiencies than with conventional solution-processed hole transport materials are achieved.
Charge transport properties in CdZnTe detectors grown by the vertical Bridgman technique
2011
Presently, a great amount of effort is being devoted to the development of CdTe and CdZnTe (CZT) detectors for a large variety of applications such as medical, industrial, and space research. We present the spectroscopic properties of some CZT crystals grown by the standard vertical Bridgman method and by the boron oxide encapsulated vertical Bridgman method, which has been recently implemented at IMEM-CNR (Parma, Italy). In this technique, the crystal is grown in an open quartz crucible fully encapsulated by a thin layer of liquid boron oxide. This method prevents contact between the crystal and the crucible, thereby allowing larger single grains with a lower dislocation density to be obta…
Comparison of two portable solid state detectors with an improved collimation and alignment device for mammographic x-ray spectroscopy
2006
We describe a portable system for mammographic x-ray spectroscopy, based on a 2 X 2 X 1 mm3 cadmium telluride (CdTe) solid state detector, that is greatly improved over a similar system based on a 3 X 3 X 2 mm3 cadmium zinc telluride (CZT) solid state detector evaluated in an earlier work. The CdTe system utilized new pinhole collimators and an alignment device that facilitated measurement of mammographic x-ray spectra. Mammographic x-ray spectra acquired by each system were comparable. Half value layer measurements obtained using an ion chamber agreed closely with those derived from the x-ray spectra measured by either detector. The faster electronics and other features of the CdTe detecto…
Combined heat and power generation with a HCPV system at 2000 suns
2015
In the framework of the FAE “Fotovoltaico ad Alta Efficienza” (“High Efficiency Photovoltaic”) Research Project funded by the Sicilian Region under the program PO FESR Sicilia 2007/2013 4.1.1.1, we have developed an innovative solar CHP system for the combined production of heat and power at the high concentration level of 2000 suns [1]. This work shows the experimental results obtained on FAE-HCPV modules and analyses the behaviour of the system. The solar radiation is concentrated on commercial InGaP/InGaAs/Ge triple-junction solar cells designed for intensive work. The primary optics is a rectangular off-axis parabolic mirror (with a size of 46x46 = 2116 cm2 in a projection normal to the…