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Dr. Ian Howard

Dr. Ian Howard

Advanced Materials and Optical Spectroscopy
Tel.: +49 721 608-28398
ian howardCqs9∂kit edu

Engesserstrasse 13, Geb. 30.34
76131 Karlsruhe


Research Interests

My research uses spectroscopy to explore the fundamental optoelectronic properties of solution-processable semiconductors. I am currently especially interested in organic semiconductors and metal organic frameworks. The ultimate goal of this research is to understand how energy flow is controlled at the nanoscale in these materials, and to use this knowledge to help design better materials for low-cost solar energy conversion.

For a complete list of publications please see my google citations, or ResearcherID profile.

Short CV

2014-present Group leader Advanced Materials and Optical Spectroscopy at KIT.
2009-2014 Alexander von Humboldt and Max Planck Fellow at the Max Planck Institute for Polymer Research in Mainz.
2005-2009 Ph.D in Physics from King's Collage, University of Cambridge. Performed in the Optoelectronics Group at the Cavendish Labratory unter the advisement of Prof. Neil Greenham. Title "Loss Mechanisms in High Open-Circuit Voltage Organic Sollar Cells".
2005 Undergraduate thesis with Prof. Sargent on solution-processed nanocrystal-baseed detectorts now commercialized through the spin-off company Invisage Inc.
2000-2005 Undergraduate degree in Engineering Science at the University of Toronto.

 

Publikationen


2019
Perovskite Solar Cells: Record Open‐Circuit Voltage Wide‐Bandgap Perovskite Solar Cells Utilizing 2D/3D Perovskite Heterostructure.
Gharibzadeh, S.; Abdollahi Nejand, B.; Jakoby, M.; Abzieher, T.; Hauschild, D.; Moghadamzadeh, S.; Schwenzer, J. A.; Brenner, P.; Schmager, R.; Haghighirad, A. A.; Weinhardt, L.; Lemmer, U.; Richards, B. S.; Howard, I. A.; Paetzold, U. W.
2019. Advanced energy materials, 9 (21), 1970079. doi:10.1002/aenm.201970079
Continuous Wave Amplified Spontaneous Emission from Mixed Cation Perovskite devices.
Brenner, P.; Bar-On, O.; Jakoby, M.; Allegro, I.; Richards, B. S.; Paetzold, U. W.; Howard, I. A.; Scheuer, J.; Lemmer, U.
2019. Conference on Lasers and Electro-Optics, JTu2A.71, OSA, Washington, D.C. doi:10.1364/CLEO_AT.2019.JTu2A.71
An enhanced energy migration strategy in upconverting nanocrystals: Color-tuning with high quantum yield.
Hudry, D.; Busko, D.; Popescu, R.; Gerthsen, D.; Howard, I. A.; Richards, B. S.
2019. Journal of materials chemistry / C, 7 (24), 7371–7377. doi:10.1039/c9tc01567a
Synthesis of dipolar molecular rotors as linkers for metal-organic frameworks.
Hamer, S.; Röhricht, F.; Jakoby, M.; Howard, I. A.; Zhang, X.; Näther, C.; Herges, R.
2019. Beilstein journal of organic chemistry, 15, 1331–1338. doi:10.3762/bjoc.15.132
Highly Efficient One-Dimensional Triplet Exciton Transport in a Palladium-Porphyrin-Based Surface-Anchored Metal-Organic Framework.
Adams, M.; Kozlowska, M.; Baroni, N.; Oldenburg, M.; Ma, R.; Busko, D.; Turshatov, A.; Emandi, G.; Senge, M. O.; Haldar, R.; Wöll, C.; Nienhaus, G. U.; Richards, B. S.; Howard, I. A.
2019. ACS applied materials & interfaces, 11 (17), 15688–15697. doi:10.1021/acsami.9b03079
A de novo strategy for predictive crystal engineering to tune excitonic coupling.
Haldar, R.; Mazel, A.; Krstić, M.; Zhang, Q.; Jakoby, M.; Howard, I. A.; Richards, B. S.; Jung, N.; Jacquemin, D.; Diring, S.; Wenzel, W.; Odobel, F.; Wöll, C.
2019. Nature Communications, 10 (1), Article: 2048. doi:10.1038/s41467-019-10011-8
Record Open‐Circuit Voltage Wide‐Bandgap Perovskite Solar Cells Utilizing 2D/3D Perovskite Heterostructure.
Gharibzadeh, S.; Abdollahi Nejand, B.; Jakoby, M.; Abzieher, T.; Hauschild, D.; Moghadamzadeh, S.; Schwenzer, J. A.; Brenner, P.; Schmager, R.; Haghighirad, A. A.; Weinhardt, L.; Lemmer, U.; Richards, B. S.; Howard, I. A.; Paetzold, U. W.
2019. Advanced energy materials, 9 (21), Article: 1803699. doi:10.1002/aenm.201803699
Coated and Printed Perovskites for Photovoltaic Applications.
Howard, I. A.; Abzieher, T.; Hossain, I. M.; Eggers, H.; Schackmar, F.; Ternes, S.; Richards, B. S.; Lemmer, U.; Paetzold, U. W.
2019. Advanced materials, 1806702. doi:10.1002/adma.201806702
Continuous wave amplified spontaneous emission in phase-stable lead halide perovskites.
Brenner, P.; Bar-On, O.; Jakoby, M.; Allegro, I.; Richards, B. S.; Paetzold, U. W.; Howard, I. A.; Scheuer, J.; Lemmer, U.
2019. Nature Communications, 10 (1), Article-Nr.: 988. doi:10.1038/s41467-019-08929-0
2018
Interface disorder in large single- and multi-shell upconverting nanocrystals.
Hudry, D.; Popescu, R.; Busko, D.; Diaz-Lopez, M.; Abeykoon, M.; Bordet, P.; Gerthsen, D.; Howard, I. A.; Richards, B. S.
2018. Journal of materials chemistry / C, 2019 (7), 1164–1172. doi:10.1039/C8TC05130E
Highly Efficient La₂O₃:Yb³⁺,Tm³⁺ Single-Band NIR-to-NIR Upconverting Microcrystals for Anti-Counterfeiting Applications.
Gao, G.; Busko, D.; Joseph, R.; Howard, I. A.; Turshatov, A.; Richards, B. S.
2018. ACS applied materials & interfaces, 10 (46), 39851–39859. doi:10.1021/acsami.8b11196
A Novel Route to Plastics Recycling via Unique, Background-free, Micro-scale Photonic Markers.
Richards, B. S.; Busko, D.; Gao, G.; Hudry, D.; Howard, I. A.; Turshatov, A.
2018. Optics and Photonics for Energy and the Environment, Singapore, 5–8 November 2018, EM2A.4, OSA, Washington (D.C.). doi:10.1364/EE.2018.EM2A.4
Reaction of porphyrin-based surface-anchored metal-organic frameworks to prolonged illumination.
Adams, M.; Baroni, N.; Oldenburg, M.; Kraffert, F.; Behrends, J.; MacQueen, R. W.; Haldar, R.; Busko, D.; Turshatov, A.; Emandi, G.; Senge, M. O.; Wöll, C.; Lips, K.; Richards, B. S.; Howard, I. A.
2018. Physical chemistry, chemical physics, 46, 29142–29151. doi:10.1039/C8CP05254A
Anisotropic energy transfer in crystalline chromophore assemblies.
Haldar, R.; Jakoby, M.; Mazel, A.; Zhang, Q.; Welle, A.; Mohamed, T.; Krolla, P.; Wenzel, W.; Diring, S.; Odobel, F.; Richards, B. S.; Howard, I. A.; Wöll, C.
2018. Nature Communications, 9 (1), Article: 4332. doi:10.1038/s41467-018-06829-3
Absolute upconversion quantum yields of blue-emitting LiYF4:Yb3+,Tm3+ upconverting nanoparticles.
Meijer, M. S.; Rojas-Gutierrez, P. A.; Busko, D.; Howard, I. A.; Frenzel, F.; Würth, C.; Resch-Genger, U.; Richards, B. S.; Turshatov, A.; Capobianco, J. A.; Bonnet, S.
2018. Physical chemistry, chemical physics, 20, 22556–22562. doi:10.1039/C8CP03935F
Inkjet-Printed Photoluminescent Patterns of Aggregation-Induced-Emission Chromophores on Surface-Anchored Metal–Organic Frameworks.
Baroni, N.; Turshatov, A.; Adams, M.; Dolgopolova, E. A.; Schlisske, S.; Hernandez-Sosa, G.; Wöll, C.; Shustova, N. B.; Richards, B. S.; Howard, I. A.
2018. ACS applied materials & interfaces, 10 (30), 25754–25762. doi:10.1021/acsami.8b05568
Up-conversion quantum yields of SrF2:Yb3+,Er3+ sub-micron particles prepared by precipitation from aqueous solution.
Kuznetsov, S.; Ermakova, Y.; Voronov, V.; Fedorov, P.; Busko, D.; Howard, I. A.; Richards, B. S.; Turshatov, A.
2018. Journal of materials chemistry / C, 6 (3), 598–604. doi:10.1039/C7TC04913G
Enhancing the photoluminescence of surface anchored metal–organic frameworks: mixed linkers and efficient acceptors.
Oldenburg, M.; Turshatov, A.; Busko, D.; Jakoby, M.; Haldar, R.; Chen, K.; Emandi, G.; Senge, M. O.; Wöll, C.; Hodgkiss, J. M.; Richards, B. S.; Howard, I. A.
2018. Physical chemistry, chemical physics, 20 (17), 11564–11576. doi:10.1039/C7CP08452H
Probing the pathways of free charge generation in organic bulk heterojunction solar cells.
Kurpiers, J.; Ferron, T.; Roland, S.; Jakoby, M.; Thiede, T.; Jaiser, F.; Albrecht, S.; Janietz, S.; Collins, B. A.; Howard, I. A.; Neher, D.
2018. Nature Communications, 9 (1), Article no 2038. doi:10.1038/s41467-018-04386-3
A method for correcting the excitation power density dependence of upconversion emission due to laser-induced heating.
Joseph, R. E.; Busko, D.; Hudry, D.; Gao, G.; Biner, D.; Krämer, K.; Turshatov, A.; Richards, B. S.; Howard, I. A.
2018. Optical materials, 82, 65–70. doi:10.1016/j.optmat.2018.05.025
Wide-range non-contact fluorescence intensity ratio thermometer based on Yb³⁺/Nd³⁺ co-doped La₂O₃ microcrystals operating from 290 to 1230 K.
Gao, G.; Busko, D.; Kauffmann-Weiss, S.; Turshatov, A.; Howard, I. A.; Richards, B. S.
2018. Journal of materials chemistry / C, 6 (15), 4163–4170. doi:10.1039/C8TC00782A
Highly photoluminescent and stable silicon nanocrystals functionalized via microwave-assisted hydrosilylation.
Beri, D.; Busko, D.; Mazilkin, A.; Howard, I. A.; Richards, B. S.; Turshatov, A.
2018. RSC Advances, 8 (18), 9979–9984. doi:10.1039/C7RA13577G
The Janus-faced chromophore : A donor-acceptor dyad with dual performance in photon up-conversion.
Kiseleva, N.; Filatov, M. A.; Oldenburg, M.; Busko, D.; Jakoby, M.; Howard, I. A.; Richards, B. S.; Senge, M. O.; Borisov, S. M.; Turshatov, A.
2018. Chemical communications, 54 (13), 1607–1610. doi:10.1039/c7cc08930a
Inkjet-printed perovskite distributed feedback lasers.
Mathies, F.; Brenner, P.; Hernandez-Sosa, G.; Howard, I. A.; Paetzold, U. W.; Lemmer, U.
2018. Optics express, 26 (2), A144 - A152. doi:10.1364/OE.26.00A144
2017
Scalable and low cost fabrication methods for wavelength tunable solution processed perovskite distributed feedback lasers.
Brenner, P.; Mathies, F.; Kapp, D.; Paetzold, U.; Quintilla, A.; Hernandez-Sosa, G.; Howard, I.; Lemmer, U.
2017. Proceedings of the European Conference on Lasers and Electro-Optics 2017, Munich, Germany, 25th - 29th June 2017, Art.Nr. JSV_3_2, OSA - The Optical Society, Wahington (DC)
N-Heteroacenes as a New Class of Non-Fullerene Electron Acceptors for Organic Bulk-Heterojunction Photovoltaic Devices.
Lami, V.; Leibold, D.; Fassl, P.; Hofstetter, Y. J.; Becker-Koch, D.; Biegger, P.; Paulus, F.; Hopkinson, P. E.; Adams, M.; Bunz, U. H. F.; Huettner, S.; Howard, I.; Bakulin, A. A.; Vaynzof, Y.
2017. Solar RRL, 1 (6), Art.Nr. 1700053. doi:10.1002/solr.201700053
Relating Structure to Efficiency in Surfactant-Free Polymer/Fullerene Nanoparticle-Based Organic Solar Cells.
Gärtner, S.; Clulow, A. J.; Howard, I. A.; Gilbert, E. P.; Burn, P. L.; Gentle, I. R.; Colsmann, A.
2017. ACS applied materials & interfaces, 9 (49), 42986–42995. doi:10.1021/acsami.7b15601
Finely-tuned NIR-to-visible up-conversion in La2O3:Yb3+,Er3+ microcrystals with high quantum yield.
Gao, G.; Busko, D.; Kauffmann-Weiss, S.; Turshatov, A.; Howard, I. A.; Richards, B. S.
2017. Journal of materials chemistry / C, 5 (42), 11010–11017. doi:10.1039/C6TC05322J
Triple cation mixed-halide perovskites for tunable lasers.
Brenner, P.; Glöckler, T.; Rueda-Delgado, D.; Abzieher, T.; Jakoby, M.; Richards, B. S.; Paetzold, U. W.; Howard, I. A.; Lemmer, U.
2017. Optical materials express, 7 (11), 4082–4094. doi:10.1364/OME.7.004082
Excitonically Coupled States in Crystalline Coordination Networks.
Haldar, R.; Mazel, A.; Joseph, R.; Adams, M.; Howard, I. A.; Richards, B. S.; Tsotsalas, M.; Redel, E.; Diring, S.; Odobel, F.; Wöll, C.
2017. Chemistry - a European journal, 23 (57), 14316–14322. doi:10.1002/chem.201702968
Facile loading of thin-film surface-anchored metal-organic frameworks with Lewis-base guest molecules.
Baroni, N.; Turshatov, A.; Oldenburg, M.; Busko, D.; Adams, M.; Haldar, R.; Welle, A.; Redel, E.; Wöll, C.; Richards, B. S.; Howard, I. A.
2017. Materials chemistry frontiers, 1 (9), 1888–1894. doi:10.1039/C7QM00142H
Up-Conversion Fluorescent Labels for Plastic Recycling: A Review.
Gao, G.; Turshatov, A.; Howard, I. A.; Busko, D.; Joseph, R.; Hudry, D.; Richards, B. S.
2017. Advanced Sustainable Systems, 1 (5), Art.Nr. 1600033. doi:10.1002/adsu.201600033
Identifying Charge-Transfer States in Polymer:Fullerene Heterojunctions by Their Emission Polarization Anisotropy.
Arndt, A. P.; Gerhard, M.; Koch, M.; Lemmer, U.; Howard, I. A.
2017. The journal of physical chemistry <Washington, DC> / C, 121 (11), 6357–6364. doi:10.1021/acs.jpcc.6b12853
Field-induced exciton dissociation in PTB7-based organic solar cells.
Gerhard, M.; Arndt, A. P.; Bilal, M.; Lemmer, U.; Koch, M.; Howard, I. A.
2017. Physical review / B, 95 (19), Art.Nr. 195301. doi:10.1103/PhysRevB.95.195301
Room-Temperature High-Efficiency Solid-State Triplet-Triplet Annihilation Up-Conversion in Amorphous Poly(olefin sulfone)s.
Turshatov, A.; Busko, D.; Kiseleva, N.; Grage, S. L.; Howard, I. A.; Richards, B. S.
2017. ACS applied materials & interfaces, 9 (9), 8280–8286. doi:10.1021/acsami.6b12625
2016
Bragg Stacks Enhancing Upconversion for Photovoltaics: A Theoretical And Experimental Analysis.
Hofmann, C. L.; Fischer, S.; Reitz, C.; Mondon, A.; Busko, D.; Howard, I.; Richards, B. S.; Goldschmidt, J. C.
2016. Light, Energy and the Environment Congress, November 14-17, 2016, Leipzig, Germany, PTh4A.5, Optical Society of America. doi:10.1364/PV.2016.PTh4A.5
Highly stable solution processed metal-halide perovskite lasers on nanoimprinted distributed feedback structures.
Brenner, P.; Stulz, M.; Kapp, D.; Abzieher, T.; Paetzold, U. W.; Quintilla, A.; Howard, I. A.; Kalt, H.; Lemmer, U.
2016. Applied physics letters, 109 (14), 141106. doi:10.1063/1.4963893
Photon Upconversion at Crystalline Organic-Organic Heterojunctions.
Oldenburg, M.; Turshatov, A.; Busko, D.; Wollgarten, S.; Adams, M.; Baroni, N.; Welle, A.; Redel, E.; Wöll, C.; Richards, B. S.; Howard, I. A.
2016. Advanced materials, 28 (38), 8477–8482. doi:10.1002/adma.201601718
Electronic transfer across crystalline thin-film surface anchored metal-organic framework (SURMOF) heterojunctions.
Oldenburg, M.; Howard, I. A.; Turshatov, A.; Baroni, N.; Wollgarten, S.; Redel, E.; Wöll, C.; Richards, B. S.
2016. SPIE Photonics Europe, Brussels, B, 3.-7. April 2016
Active heterostructure of crystalline thin-film surface anchored metal-organic frameworks for optoelectronic applications.
Oldenburg, M.; Howard, I. A.; Turshatov, A.; Baroni, N.; Wollgarten, S.; Redel, E.; Wöll, C.
2016. 80. Jahrestagung der DPG und DPG-Frühjahrstagung der Sektion Kondensierte Materie, Fachverband Chemische Physik und Polymerphysik, Regensburg, 6.-11.März 2016. Verhandlungen der Deutschen Physikalischen Gesellschaft, R.6, B.51(2016) CPP32.9, H37
Loss mechanisms in organic solar cells based on perylene diimide acceptors studied by time-resolved photoluminescence.
Gerhard, M.; Gehring, D.; Howard, I. A.; Arndt, A. P.; Bilal, M.; Rahimi-Iman, A.; Lemmer, U.; Laquai, F.; Koch, M.
2016. Organic Photonics VII. Ed.: D. Cheyns, 98950H, SPIE, Bellingham. doi:10.1117/12.2227672
2015
Temperature- and energy-dependent separation of charge-transfer states in PTB7-based organic solar cells.
Gerhard, M.; Arndt, A. P.; Howard, I. A.; Rahimi-Iman, A.; Lemmer, U.; Koch, M.
2015. The journal of physical chemistry <Washington, DC> / C, 119 (51), 28309–28318. doi:10.1021/acs.jpcc.5b09842
Photoinduzierte Erzeugung von Ladungsträgern in epitaktischen MOF-Dünnschichten: hohe Leistung aufgrund einer indirekten elektronischen Bandlücke?.
Liu, J.; Zhou, W.; Liu, J.; Howard, I.; Kilibarda, G.; Schlabach, S.; Coupry, D.; Addicoat, M.; Yoneda, S.; Tsutsui, Y.; Sakurai, T.; Seki, S.; Wang, Z.; Lindemann, P.; Redel, E.; Heine, T.; Wöll, C.
2015. Angewandte Chemie, 127, 7549–7553. doi:10.1002/ange.201501862
Photoinduced charge-carrier generation in epitaxial MOF thin films: High efficiency as a result of an indirect electronic band gap?.
Liu, J.; Zhou, W.; Liu, J.; Howard, I.; Kilibarda, G.; Schlabach, S.; Coupry, D.; Addicoat, M.; Yoneda, S.; Tsutsui, Y.; Sakurai, T.; Seki, S.; Wang, Z.; Lindemann, P.; Redel, E.; Heine, T.; Wöll, C.
2015. Angewandte Chemie / International edition, 54 (25), 7441–7445. doi:10.1002/anie.201501862
The impact of donor-acceptor phase separation on the charge carrier dynamics in pBTTT:PCBM photovoltaic blends.
Gehrig, D. W.; Howard, I. A.; Sweetnam, S.; Burke, T. M.; McGehee, M.; Laquai, F.
2015. Macromolecular rapid communications, 36 (11), 1054–1060. doi:10.1002/marc.201500112
Time-resolved charge-transfer state emission in organic solar cells : Temperature and blend composition dependences of interfacial traps.
Arndt, A. P.; Gerhard, M.; Quintilla, A.; Howard, I. A.; Koch, M. W.; Lemmer, U.
2015. The journal of physical chemistry <Washington, DC> / C, 119 (24), 13516–13523. doi:10.1021/acs.jpcc.5b03507
2014
Control of charge generation and recombination in ternary polymer/polymer:fullerene photovoltaic blends using amorphous and semi-crystalline copolymers as donors.
Mangold, H.; Bakulin, A. A.; Howard, I. A.; Kästner, C.; Egbe, D. A. M.; Hoppe, H.; Laquai, F.
2014. Physical chemistry, chemical physics, 16, 20329–20337. doi:10.1039/C4CP01883D