|   | 
Details
   web
Records
Author Bhatia, H.; Keshavarz, M.; Martin, C.; Van Gaal, L.; Zhang, Y.; de Coen, B.; Schrenker, N.J.; Valli, D.; Ottesen, M.; Bremholm, M.; Van de Vondel, J.; Bals, S.; Hofkens, J.; Debroye, E.
Title Achieving High Moisture Tolerance in Pseudohalide Perovskite Nanocrystals for Light-Emitting Diode Application Type A1 Journal Article
Year (down) 2023 Publication ACS Applied Optical Materials Abbreviated Journal ACS Appl. Opt. Mater.
Volume 1 Issue 6 Pages 1184-1191
Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Abstract The addition of potassium thiocyanate (KSCN) to the FAPbBr3 structure and subsequent post-treatment of nanocrystals (NCs) lead to high quantum confinement, resulting in a photoluminescent quantum yield (PLQY) approaching unity and microsecond decay times. This synergistic approach demonstrated exceptional stability under humid conditions, retaining 70% of the PLQY for over a month, while the untreated NCs degrade within 24 h. Additionally, the devices incorporating the post-treated NCs displayed 1.5% external quantum efficiency (EQE), a 5-fold improvement over untreated devices. These results provide promising opportunities for the use of perovskites in moisture-stable optoelectronics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2023-06-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2771-9855 ISBN Additional Links UA library record
Impact Factor Times cited Open Access Not_Open_Access
Notes Hercules Foundation, HER/11/14 ; European Commission; Ministerio de Ciencia e Innovaci?n, PID2021-128761OA-C22 ; European Regional Development Fund; Vlaamse regering, CASAS2 Meth/15/04 ; Fonds Wetenschappelijk Onderzoek, 1238622N 1514220N 1S45223N G.0B39.15 G.0B49.15 G098319N S002019N ZW15_09-GOH6316 ; Onderzoeksraad, KU Leuven, C14/19/079 db/21/006/bm iBOF-21-085 STG/21/010 ; Junta de Comunidades de Castilla-La Mancha, SBPLY/21/180501/000127 ; H2020 European Research Council, 642196 815128 ; Approved Most recent IF: NA
Call Number EMAT @ emat @c:irua:201011 Serial 8975
Permanent link to this record
 

 
Author Bhatia, H.; Martin, C.; Keshavarz, M.; Dovgaliuk, I.; Schrenker, N.J.; Ottesen, M.; Qiu, W.; Fron, E.; Bremholm, M.; Van de Vondel, J.; Bals, S.; Roeffaers, M.B.J.; Hofkens, J.; Debroye, E.
Title Deciphering the role of water in promoting the optoelectronic performance of surface-engineered lead halide perovskite nanocrystals Type A1 Journal article
Year (down) 2023 Publication ACS applied materials and interfaces Abbreviated Journal
Volume 15 Issue 5 Pages 7294-7307
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Lead halide perovskites are promising candidates for applicability is limited by their structural instability toward moisture. Although a deliberate addition of water to the precursor solution has recently been shown to improve the crystallinity and optical properties of perovskites, the corresponding thin films still do not exhibit a near-unity quantum yield. Herein, we report that the direct addition of a minute amount of water to post-treated substantially enhances the stability while achieving a 95% photoluminescence quantum yield in a NC thin film. We unveil the mechanism of how moisture assists in the formation of an additional NH4Br component. Alongside, we demonstrate the crucial role of moisture in assisting localized etching of the perovskite crystal, facilitating the partial incorporation of NH4+, which is key for improved performance under ambient conditions. Finally, as a proof-of-concept, the application of post-treated and watertreated perovskites is tested in LEDs, with the latter exhibiting a superior performance, offering opportunities toward commercial application in moisture-stable optoelectronics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000931729400001 Publication Date 2023-01-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.5 Times cited 3 Open Access Not_Open_Access
Notes H.B. would like to express her sincere gratitude to Dr. Peter Erk (formerly BASF SE, Germany) for very insightful discussions. The authors acknowledge financial support from the Research Foundation-Flanders (FWO grant numbers S002019N, 1514220N, G.0B39.15, G.0B49.15, G098319N, and ZW15_09-GOH6316) , the KU Leuven Research Fund (C14/19/079, iBOF-21-085 PERSIST, and STG/21/010) , the Flemish government through long-term structural funding Methusalem (CASAS2, Meth/15/04) , the Hercules Founda-tion (HER/11/14) , and the ERC through the Marie Curie ITN iSwitch Ph.D. fellowship to H.B. (grant number 642196) . C.M. acknowledges the financial support from grants PID2021-128761OA-C22 funded by MCIN/AEI/10.13039/501100011033 by the ?European Union? and SBPLY/21/180501/000127 funded by JCCM and by the EU through Fondo Europeo de Desarollo Regional? (FEDER) . Martin Bremholm and Martin Ottesen acknowledge funding from the Danish Council for Independent Research, Natural Sciences, under the Sapere Aude program (grant no. 7027-00077B) and VILLUM FONDEN through the Centre of Excellence for Dirac Materials (grant no. 11744) . Affiliation with the Center for Integrated Materials Research (iMAT) at Aarhus University is gratefully acknowledged.-N.J.S. acknowledges financial support from the research foundation Flanders (FWO) through a postdoctoral fellowship (FWO grant no. 1238622N) . S.B. acknowledges financial support from the European Commission by the ERC Consolidator grant REALNANO (no. 815128) . Approved Most recent IF: 9.5; 2023 IF: 7.504
Call Number UA @ admin @ c:irua:195375 Serial 7293
Permanent link to this record
 

 
Author Sharafi, L.; Zarafshani, K.; Keshavarz, M.; Azadi, H.; Van Passel, S.
Title Farmers' decision to use drought early warning system in developing countries Type A1 Journal article
Year (down) 2021 Publication Science Of The Total Environment Abbreviated Journal Sci Total Environ
Volume 758 Issue Pages 142761
Keywords A1 Journal article; Engineering Management (ENM)
Abstract Drought is a persistent, sluggish natural disaster in developing countries that has generated a financial burden and an unstable climate. Farmers should adopt early warning systems (EWS) in their strategies for monitoring drought to reduce its serious consequences. However, farmers in developing countries are reluctant to use EWS as their management strategies. Hence, the aim of this study was to investigate the decision of farmers to use climate knowledge through the model of farming activity in Kermanshah Township, Iran. A surveyor questionnaire was used to gather data from 370 wheat farmers using random sampling methods inmulti-stage clusters. Results revealed that the decision to use climate information is affected by personal factors, attitude towards climate information, objectives of using climate information, and external/physical farming factors. The result of this study has implications for drought management practitioners. To be specific, the results can aid policymakers to design early alert programs to minimize the risk of drought and thus move from conventional to climate smart agriculture. (C) 2020 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000605623800001 Publication Date 2020-10-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0048-9697 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.9 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.9
Call Number UA @ admin @ c:irua:176030 Serial 6924
Permanent link to this record
 

 
Author Sharafi, L.; Zarafshani, K.; Keshavarz, M.; Azadi, H.; Van Passel, S.
Title Drought risk assessment: Towards drought early warning system and sustainable environment in western Iran Type A1 Journal Article
Year (down) 2020 Publication Ecological Indicators Abbreviated Journal Ecological Indicators
Volume 114 Issue Pages 106276
Keywords A1 Journal Article; Drought; Early warning system; Risk management; Vulnerability; Environmental risk; Resilient farming; Engineering Management (ENM) ;
Abstract Prolonged drought is considered as a creeping natural hazard, which has created a financial burden and unsustainable environment in Iran. Moreover, the effect of drought phenomenon in rural areas is more extensive, causing significant challenges to the rural economy in general and agricultural production in particular. A common strategy to manage drought is based on crisis management (ex-ante). However, for effective drought management, risk management seems to be more in line with drought early warning systems. This quantitative study used risk assessment, which is the function of two elements such as hazard (SPI and SDI indices) and vulnerability (exposure, sensitivity, and adaptive capacity). This study aims to build the foundations for drought early warning systems in limited resource areas such as Kermanshah Township in the northwestern part of Iran. The population of this study comprised of wheat farmers in which 293 farmers were selected using multistage cluster sampling method. In the next step, the drought risk map for Kermanshah Township was developed, which revealed that the majority of villages are at intense environmental risk. The result of this study has implications for drought management practitioners. For example, the results can aid policymakers in the design of an early warning system in order to reduce risk and thus empower farmers toward resilient farming.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000559966500006 Publication Date 2020-04-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1470160X ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number ENM @ enm @c:irua:170071 Serial 6380
Permanent link to this record
 

 
Author Yuan, H.; Debroye, E.; Bladt, E.; Lu, G.; Keshavarz, M.; Janssen, K.P.F.; Roeffaers, M.B.J.; Bals, S.; Sargent, E.H.; Hofkens, J.
Title Imaging heterogeneously distributed photo-active traps in perovskite single crystals Type A1 Journal article
Year (down) 2018 Publication Advanced materials Abbreviated Journal Adv Mater
Volume 30 Issue 30 Pages 1705494
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Organic-inorganic halide perovskites (OIHPs) have demonstrated outstanding energy conversion efficiency in solar cells and light-emitting devices. In spite of intensive developments in both materials and devices, electronic traps and defects that significantly affect their device properties remain under-investigated. Particularly, it remains challenging to identify and to resolve traps individually at the nanoscopic scale. Here, photo-active traps (PATs) are mapped over OIHP nanocrystal morphology of different crystallinity by means of correlative optical differential super-resolution localization microscopy (Delta-SRLM) and electron microscopy. Stochastic and monolithic photoluminescence intermittency due to individual PATs is observed on monocrystalline and polycrystalline OIHP nanocrystals. Delta-SRLM reveals a heterogeneous PAT distribution across nanocrystals and determines the PAT density to be 1.3 x 10(14) and 8 x 10(13) cm(-3) for polycrystalline and for monocrystalline nanocrystals, respectively. The higher PAT density in polycrystalline nanocrystals is likely related to an increased defect density. Moreover, monocrystalline nanocrystals that are prepared in an oxygen and moisture-free environment show a similar PAT density as that prepared at ambient conditions, excluding oxygen or moisture as chief causes of PATs. Hence, it is conduded that the PATs come from inherent structural defects in the material, which suggests that the PAT density can be reduced by improving crystalline quality of the material.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000428793600009 Publication Date 2018-02-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 19.791 Times cited 29 Open Access OpenAccess
Notes ; The authors acknowledge financial support from the Research Foundation-Flanders (FWO, grant G.0197.11, G.0962.13, G0B39.15, ZW1509 GOH6316N, postdoctoral fellowships to H.Y., E.D., and K.P.F.J., doctoral fellowship to E.B.), KU Leuven Research Fund (C14/15/053), the Flemish government through long term structural funding Methusalem (CASAS2, Meth/15/04), the Hercules foundation (HER/11/14), the Belgian Federal Science Policy Office (IAP-PH05), the EC through the Marie Curie ITN project iSwitch (GA-642196), and the ERC project LIGHT (GA-307523). S.B. acknowledges financial support from European Research Council (ERC Starting Grant #335078-COLOURATOMS). G.L. acknowledges Key University Science Research Project of Jiangsu Province (No. 17KJA150005). E.H.S. acknowledges support from the Ontario Research Fund – Research Excellence Program. ; ecassara Approved Most recent IF: 19.791
Call Number UA @ lucian @ c:irua:150826UA @ admin @ c:irua:150826 Serial 4970
Permanent link to this record