ORCID Profile
0000-0002-7713-2154
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Theory and Design of Materials | Structural Chemistry and Spectroscopy | Theoretical and Computational Chemistry not elsewhere classified | Nanotechnology | Molecular and Organic Electronics | Condensed Matter Characterisation Technique Development | Nanoelectronics | Physical Chemistry (Incl. Structural)
Expanding Knowledge in the Physical Sciences | Industrial Energy Conservation and Efficiency | Residential Energy Conservation and Efficiency | Solar-Photovoltaic Energy |
Publisher: SPIE
Date: 27-11-2012
DOI: 10.1117/12.999270
Publisher: AIP Publishing
Date: 10-10-2016
DOI: 10.1063/1.4963705
Abstract: Secondary photocurrents offer an alternative mechanism to photomultiplier tubes and avalanche diodes for making high gain photodetectors that are able to operate even at extremely low light conditions. While in the past secondary currents were studied mainly in ordered crystalline semiconductors, disordered systems offer some key advantages such as a potentially lower leakage current and typically longer photocarrier lifetimes due to trapping. In this work, we use numerical simulations to identify the critical device and material parameters required to achieve high photocurrent and gain in steady state. We find that imbalanced mobilities and suppressed, non-Langevin-type charge carrier recombination will produce the highest gain. A low light intensity, strong electric field, and a large single carrier space charge limited current are also beneficial for reaching high gains. These results would be useful for practical photodetector fabrication when aiming to maximize the gain.
Publisher: Wiley
Date: 23-07-2012
Publisher: SPIE
Date: 18-08-2005
DOI: 10.1117/12.614864
Publisher: Wiley
Date: 11-10-2023
Publisher: AIP Publishing
Date: 28-02-2011
DOI: 10.1063/1.3557503
Abstract: The electric field and temperature dependence of the electron mobility is studied comparatively in the bulk of fullerene (C60) diodes and at the interface with dielectric of organic field effect transistors (OFETs). Electron mobility values follow a Poole–Frenkel-type electric field dependence in both types of devices. The activation energy for electron transport is electric field dependent and follows the square root law of field in both devices as predicted by Gill’s law. The same Gill’s energy EGill=34 meV is measured in diodes and OFETs, which corresponds well to Meyer–Neldel energy (EMN=35 meV). It is shown that both the electric field and charge carrier concentration must be accounted for the description of disordered charge transport.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TC30472H
Publisher: American Chemical Society (ACS)
Date: 21-01-2014
DOI: 10.1021/PH400047B
Publisher: American Chemical Society (ACS)
Date: 20-11-2015
Publisher: American Physical Society (APS)
Date: 05-05-2005
Publisher: AIP Publishing
Date: 07-07-2014
DOI: 10.1063/1.4887316
Abstract: Photovoltaic performance in relation to charge transport is studied in efficient (7.6%) organic solar cells (PTB7:PC71BM). Both electron and hole mobilities are experimentally measured in efficient solar cells using the resistance dependent photovoltage technique, while the inapplicability of classical techniques, such as space charge limited current and photogenerated charge extraction by linearly increasing voltage is discussed. Limits in the short-circuit current originate from optical losses, while charge transport is shown not to be a limiting process. Efficient charge extraction without recombination can be achieved with a mobility of charge carriers much lower than previously expected. The presence of dispersive transport with strongly distributed mobilities in high efficiency solar cells is demonstrated. Reduced non-Langevin recombination is shown to be beneficial for solar cells with imbalanced, low, and dispersive electron and hole mobilities.
Publisher: Springer Science and Business Media LLC
Date: 22-07-2014
DOI: 10.1038/SREP05695
Publisher: Wiley
Date: 09-10-2014
Publisher: Elsevier BV
Date: 12-2013
Publisher: Elsevier BV
Date: 2016
Publisher: Elsevier BV
Date: 08-2017
Publisher: Springer Science and Business Media LLC
Date: 31-08-2016
Publisher: Elsevier BV
Date: 08-2006
Publisher: IOP Publishing
Date: 19-11-2013
Publisher: American Physical Society (APS)
Date: 20-07-2005
Publisher: Wiley
Date: 10-2012
Publisher: Elsevier BV
Date: 2015
Publisher: Elsevier BV
Date: 2021
Publisher: AIP Publishing
Date: 04-08-2014
DOI: 10.1063/1.4891369
Abstract: Charge carrier recombination is studied in operational organic solar cells made from the polymer:fullerene system PCDTBT:PC71BM (poly[N-9′′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)]: [6,6]-phenyl-C70-butyric acid methyl ester). A newly developed technique High Intensity Resistance dependent PhotoVoltage is presented for reliably quantifying the bimolecular recombination coefficient independently of variations in experimental conditions, thereby resolving key limitations of previous experimental approaches. Experiments are performed on solar cells of varying thicknesses and varying polymeric molecular weights. It is shown that solar cells made from low molecular weight PCDTBT exhibit Langevin recombination, whereas suppressed (non-Langevin) recombination is found in solar cells made with high molecular weight PCDTBT.
Publisher: American Physical Society (APS)
Date: 27-01-2005
Publisher: American Physical Society (APS)
Date: 19-07-2012
Publisher: AIP Publishing
Date: 22-11-2005
DOI: 10.1063/1.2137454
Abstract: Ambipolar charge carrier mobility and recombination in bulk-heterojunction solar cells based on the mixture of regioregular poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene (PCBM) has been studied using injection current transients. The experimental results demonstrate double injection with bimolecular recombination limiting the injection current. We found that charge carrier bimolecular recombination is significantly reduced compared to Langevin recombination. We have measured the temperature and electric field dependence of the reduced bimolecular recombination coefficient and the results suggest that the electron and hole pathways are different and the recombination is controlled by the probability of the carriers to meet at the polymer/PCBM interface.
Publisher: Elsevier BV
Date: 07-2006
Publisher: Springer Science and Business Media LLC
Date: 28-04-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 31-07-2014
DOI: 10.1039/C4TC90093F
Publisher: Springer Science and Business Media LLC
Date: 28-04-2015
DOI: 10.1038/SREP09949
Abstract: Light harvesting systems based upon disordered materials are not only widespread innature, but are also increasingly prevalent in solar cells and photodetectors.Ex les include organic semiconductors, which typically possess low charge carriermobilities and Langevin-type recombination dynamics – both of whichnegatively impact the device performance. It is accepted wisdom that the“drift distance” (i.e., the distance a photocarrier driftsbefore recombination) is defined by the mobility-lifetime product in solar cells. Wedemonstrate that this traditional figure of merit is inadequate for describing thecharge transport physics of organic light harvesting systems. It is experimentallyshown that the onset of the photocarrier recombination is determined by theelectrode charge and we propose the mobility-recombination coefficient product as analternative figure of merit. The implications of these findings are relevant to awide range of light harvesting systems and will necessitate a rethink of thecritical parameters of charge transport.
Publisher: AIP Publishing
Date: 13-11-2013
DOI: 10.1063/1.4829456
Abstract: The relationship between charge carrier lifetime and mobility in a bulk heterojunction based organic solar cell, utilizing diketopyrrolopyrole-naphthalene co-polymer and PC71BM in the photoactive blend layer, is investigated using the photoinduced charge extraction by linearly increasing voltage technique. Light intensity, delay time, and temperature dependent experiments are used to quantify the charge carrier mobility and density as well as the temperature dependence of both. From the saturation of photoinduced current at high laser intensities, it is shown that Langevin-type bimolecular recombination is present in the studied system. The charge carrier lifetime, especially in Langevin systems, is discussed to be an ambiguous and unreliable parameter to determine the performance of organic solar cells, because of the dependence of charge carrier lifetime on charge carrier density, mobility, and type of recombination. It is revealed that the relation between charge mobility (μ) and lifetime (τ) is inversely proportional, where the μτ product is independent of temperature. The results indicate that in photovoltaic systems with Langevin type bimolecular recombination, the strategies to increase the charge lifetime might not be beneficial because of an accompanying reduction in charge carrier mobility. Instead, the focus on non-Langevin mechanisms of recombination is crucial, because this allows an increase in the charge extraction rate by improving the carrier lifetime, density, and mobility simultaneously.
Publisher: Cambridge University Press (CUP)
Date: 11-10-2017
DOI: 10.1017/S1744137417000479
Abstract: This paper analyses the origin of innovation using institutional economic theory. Because of distributed information and fundamental uncertainty, an efficient institutional context for the economic organization of innovation in its early stages is often that of a common pool resource. The theory of the innovation commons draws upon Hayek, Williamson and Ostrom to present the innovation problem as a combined knowledge problem, implicit contracting problem and collective action governance problem. Innovation commons theory also implies that Kirzner's model of entrepreneurial opportunity discovery extends to higher-order groups, suggesting a multilevel selection model of economic evolution.
No related organisations have been discovered for Almantas Pivrikas.
Start Date: 01-2012
End Date: 01-2015
Amount: $375,000.00
Summary: High performance organic optoelectronic devices - the role of charge carrier lifetime. Organic solar cells offer a sustainable solution to energy production helping to address the challenge of climate change. This project aims to understand the processes that control device performance and to improve solar cells based upon organic semiconductors with the potential to be extremely cheap, recyclable, and mechanically flexible.
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2021
End Date: 04-2025
Amount: $460,000.00
Summary: Pathways for performance improvements of organic light emitting diodes . Organic light-emitting diodes (OLEDs) represent the next generation technology for displays and lighting. Despite their rapid uptake, one of the factors limiting their application in lighting is the efficiency roll-off at high brightness. This project aims to work towards solutions for this problem using an innovative combination of simulation studies and experimental work. Expected outcomes include improved theoretical and .... Pathways for performance improvements of organic light emitting diodes . Organic light-emitting diodes (OLEDs) represent the next generation technology for displays and lighting. Despite their rapid uptake, one of the factors limiting their application in lighting is the efficiency roll-off at high brightness. This project aims to work towards solutions for this problem using an innovative combination of simulation studies and experimental work. Expected outcomes include improved theoretical and experimental approaches leading to new design rules for OLEDs. This should provide significant benefits such as a pathway for development of improved efficient, high brightness OLEDs for applications in low energy consumption lighting and long-lasting, bright displays. Read more Read less
Funder: Australian Research Council
View Funded Activity